Upgraded to the latest and upgraded app. Now live feed only transmits about 40 feet without interference / wash-out / pixilation. How to fix or rollback?

Try rolling back your Mavic Pro's firmware to .0200.  Skip over .0300.

.0300 no issues. Don't see any firmaware options listed in DJI Assistant. Do I need Dumbldore?

Your problems are not with 0.400 , I would try rolling back your go4 app first. Also remember 0.200 had many more problems than 0.400, if you just go by this forum, it had 3 times more problems. FW is not your problem.

Do you use an Android display ?
The problem is most likely associated with latest DJI Go 4 App'.

homeshooter Posted at 2018-7-30 14:55
.0300 no issues. Don't see any firmaware options listed in DJI Assistant. Do I need Dumbldore?

No you don't need Dumbldore.  Have been using DJI's Assistant-2 to Update or Rollback firmware.

Reason I say skip over .0300 is because I started seeing occassional Pixelation / Smearing / Blurring problem after upgrading from .0200 to .0300.

Hallmark and Aardvark is correct, your issues may not be with the firmware but with the Go4 app itself, if you on Android you should roll back the app first to around 4.2.12 via apk pure and test this, should fix your issues.

https://www.apkmirror.com/?post_ ... htype=apk&s=dji

What version of GO-4 was running on your SmartDevice before and currently?  

Suren Posted at 2018-7-30 19:33
Hallmark and Aardvark is correct, your issues may not be with the firmware but with the Go4 app itself, if you on Android you should roll back the app first to around 4.2.12 via apk pure and test this, should fix your issues.

https://www.apkmirror.com/?post_type=app_release&searchtype=apk&s=dji

Whether the OP's Live view ''interference / wash-out / pixilation'' problem was caused by updating Mavic Pro to .0400 FW or updating GO-4 App; OP's pixelation problem, like others have reported is a DJI induced programming Bug.

DJI absolutely needs to stop with scripted fixes, and start working with Mavic owners to get problems resolved.  That includes diverse problems seen by Mavic Air owners too!

Hi, sorry about the trouble that it caused if may I ask what phone are you using? I would advise restoring factory defaults and refresh the firmware of your drone using the DJI Assistant 2 to see if there will be changes as well, however, if it's still the same, please send a short video of this issue for further analysis. Please see the link below. Thank you.
https://www.dji.com/mavic/info#downloads

I'm using an LG G5 Android phone. It's the only device I've ever used. Both device and aircraft are using the latest DJI updates.

homeshooter Posted at 2018-7-31 14:22
I'm using an LG G5 Android phone. It's the only device I've ever used. Both device and aircraft are using the latest DJI updates.

Hi, thanks for the response. I would like to clarify if you were able to do the troubleshooting? Did you re-calibrate the IMU and compass after doing the DJI Assistant 2? Please hit "Reply" for me to be notified. Thanks for the support.

DJI Tony Posted at 2018-8-1 11:48
Hi, thanks for the response. I would like to clarify if you were able to do the troubleshooting? Did you re-calibrate the IMU and compass after doing the DJI Assistant 2? Please hit "Reply" for me to be notified. Thanks for the support.

In DJI Assistant I cannot access previous firmware versions and reports FAIL when attempting to restore factory defaults.

homeshooter Posted at 2018-8-16 15:21
In DJI Assistant I cannot access previous firmware versions and reports FAIL when attempting to restore factory defaults.

Hi, sorry for the troubles that it caused. What type of computer are you using? Did you try to uninstall and re-install the application? Please keep us posted on the latest progress. Thank you.