After doing the update on October 8th to the drone which mainly added Occusync 2.0 functionality to the drone I have had issues with the drone dropping GPS mid flight. Before doing the update I never had issues with GPS signal at all and at that point I had logged more than 20hrs on this drone. After completing the recent update the drone has had GPS as well as compass issues. The GPS is usually lost at some point during mid flight for maybe 20-30 seconds then comes back then loses it again and sometimes I never regain the GPS signal. I have calibrated the IMU, calibrated the compass, and completed a Gimbal calibration. The odd thing is that doing the preflight checklist and during warm up/acquiring satellites there are no issues however I have been getting a compass calibration error recently before every flight which is also new. I don't know what else to do in order to resolve this issue. I am hoping that someone can give me some guidance on how to get this issue resolved. Thanks for any help you can provide.

GPS is normally very reliable.
There are only three issues that would cause your Phantom to drop GPS.
1.  Flying under cover that blocks the drone's skyview
2.  A hardware fault or disconnected GPS unit
3. A compass error

No amount of recalibrating anything will fix the issue you describe.

To solve the mystery, you need to work out whether you losing GPS satellite signal or if the Phantom still has GPS signal but is switching to atti and not using the GPS data.
A look at the recorded flight data will show which it is.

The mention of a compass error before every flight is suspicious.
Where are you launching from?
A compass error isn't a fault in the compass.
It's your compass warning you of a magnetic influence close by.
The correct action is to move away from the problem it's warning you about.

Hi, we're sorry that you're having a problem with your Phantom 4 Pro V2.0. Regarding your concern, have you tried to test and check the GPS signal of your drone into different/open area location? If not, can you please try to fly your drone in an open area so we can check? Should you have further question, please don't hesitate to reach us. Thank you.

I agree with lab most likely scenario is that you are having issues with compass in some form. This is causing the drone to switch off the gps.
If you had no issues prior to the update it may be pos you need to either redo the update or roll back to the previous version.
I would recommend doing a factory reset first then try redoing the update this may require a cple of tries to get a functional bug free setup.
I suggest you upload your flight log and post a link to the file here once you have finished this way we can confirm what may be causing the issue.

https://www.phantomhelp.com/logviewer/Upload/

Thanks for the replies to my post! I guess I should clarify my first post a bit. The Compass error wasn't an error it was a prompt to re-calibrate the compass before each flight. However, since the update that was issued the same day that I posted my first post on 10/23 I have not had that issue. The GPS issue however continues to be a problem. I understand the issues that can effect GPS, which was stated in labs post above.

What doesn't make sense is that the issue with GPS never surfaced until after the update that I did on October the 8th. The odd thing is that the GPS signal is fine when I take off and then mid flight it will report a weak signal and switch to ATTI mode. Someone stated to change flight locations that I have done, but again I am flying it in the same location as I did before when I never had any errors then after the update I began to see the errors with GPS dropping off mid flight and switching to ATTI mode, which leads me to believe it is something to do with the update causing the drone to malfunction/drop GPS. I will add a link to some flight data so you guys can take a look maybe determine from the data what is causing the issue.

Here is the link to my flight data: https://app.airdata.com/share/SCWroM

Let me know if this helps you guys determine the cause of my GPS issues. Thanks!

This link is to more of my flight data:  https://app.airdata.com/share/PQtMPE

Two flights are particularly interesting: October 12th and 23rd. You will notice the drone has good GPS signal at takeoff however dropping it midway during the flight, but the most odd part is that the data shows the drone path stopping somewhere far away from where I actually took off and landed. So I don't know what would cause this because in both instances I landed the drone exactly where I took off from. It shows the drone path leading off very far from where the drone actually went, which I find quite odd. This only happened in these two flights after I analyzed the flight data.

rydacdronz Posted at 11-7 09:38
Here is the link to my flight data: https://app.airdata.com/share/SCWroM

Let me know if this helps you guys determine the cause of my GPS issues. Thanks!

Airdata makes it difficult to analyse.
If you could go to http://www.phantomhelp.com/LogViewer/Upload/
Follow the instructions there to upload your flight record from your phone or tablet.
Come back and post a link to the report it gives you, that would make it a lot easier to see what's happening.

Ok I will do that with a flight from this morning. I wasn't thinking your right Airdata is much more complex in terms of data, so let me go through the link you have attached above so that I can upload the DJI logs.

Ok here is a link to the flight log from the flight I did this morning. It is a great example of the issue I have been having with the GPS having satellites locked at the beginning of the flight then mid way through dropping satellites switching to ATTI mode. Take a look at the following flight hopefully this will be more helpful in analyzing what it is that I may be experiencing causing my malfunctions with GPS. Thanks for the help! Here is the link: http://www.phantomhelp.com/LogViewer/55YE1Y700GS40ORRLDFJ/

Here is the link to my flight Log from this morning: RD DJI Phantom 4 Pro V2.0 11/08/18

rydacdronz Posted at 11-8 11:19
Ok here is a link to the flight log from the flight I did this morning. It is a great example of the issue I have been having with the GPS having satellites locked at the beginning of the flight then mid way through dropping satellites switching to ATTI mode. Take a look at the following flight hopefully this will be more helpful in analyzing what it is that I may be experiencing causing my malfunctions with GPS. Thanks for the help! Here is the link: http://www.phantomhelp.com/LogViewer/55YE1Y700GS40ORRLDFJ/

Thanks .. that clearly shows the issue.
Back in my first post I said:
GPS is normally very reliable.
There are only three issues that would cause your Phantom to drop GPS.
  1.  Flying under cover that blocks the drone's skyview
  2.  A hardware fault or disconnected GPS unit
  3. A compass error
Normally if you are flying in the open, you get GPS reception and you never lose it.
The data shows quite clearly that the issue with your Phantom is not 1 or 3 so that leaves #2:
A hardware fault or disconnected GPS unit.
Your Phantom is seeing the number of sats intermittently drop to zero for periods of 0.4 secs to 4 minutes.
It looks very much like either a faulty GPS receiver or a very poor connection from the GPS receiver to the mainboard.

You say this started after a firmware update?
If so I'd attempt to reverse that firmware update and go back to the previous firmware ASAP and fly in a large, open area with light winds a few times to see if that fixes it.
Otherwise I would strongly recommend you get that looked at.
The Phantom should not behave this way and it could prevent it being able to RTH or cause control difficulties.

DJI Natalia Posted at 2018-10-23 14:59
Hi, we're sorry that you're having a problem with your Phantom 4 Pro V2.0. Regarding your concern, have you tried to test and check the GPS signal of your drone into different/open area location? If not, can you please try to fly your drone in an open area so we can check? Should you have further question, please don't hesitate to reach us. Thank you.

Hello i'm having a same problem with my phantom 4 pro V2 drone. I mainly use in open areas, in countryside. These problems occured last year after the update i think. Before it was normal. It is really annoying. When the drone in a mid flight gps signal drops, and the drones camera has glitching in a mid air.

One of our Phantom 4 Pros that we use for mapping is experiencing this issue.  It started during a Drone Deploy mission where it would stop mid mission and would just pause the mission and the resume button would be available.  We would click it and then after 30 seconds it would continue.  We tried the drone out after using regular dji app and shortly after every take off, about 1 to 2 minutes later the unit would loss gps.  We would land it, restart it and it is fine again for only 2 minutes, rinse and repeat.  We brought it in to our local DJI dealer where they stripped the drone apart and put it back together to make sure the connection was fine for the GPS.  It was fine for maybe 2 flights and right back to where we started.  The shop indicated everything looked fine but they did unplug and plug the gps unit back in so maybe that helped reset it for a couple of fights.  Either way this unit is dead to us as after 9 months of trying to fix it and self testing nothing seemed to have fixed the issue including switching controllers in the case someone was thinking that could have been the issue.  We have flown it for almost 175 mapping missions alone not to mention a ton of other random things so she is ready to retire.