I get the information below once in a while, it is with >13 satellites and within sight, and shorts distance 200-300 meters, the message is typically less than 2 sec.and is rarely repeated within the same flight.
Any ideas ?

Weak signal. Adjust antennas (Code: 80016). Aircraft not connected to RC

Is there any metal between you and the drone.Are you pointing the antennas toward  the drone.
Did you calabrate the Drone and Controllers near any metal. Car, fence, rebar in concreat, wifi, electric fence. All can cause false calibration.

Donut Michigan Posted at 5-15 11:06
Is there any metal between you and the drone.Are you pointing the antennas toward  the drone.
Did you calabrate the Drone and Controllers near any metal. Car, fence, rebar in concreat, wifi, electric fence. All can cause false calibration.

Always in open fields, no powerlines or metal, calibrate only done once in open field as new.

Is the drone disconnecting from the controller, or is the message coming up for no reason? If the drone is disconnecting or you are having signal issues, try putting it in 5.8 gigahertz instead of 2.4. This will help with signal interference.

Drone Exploration Posted at 5-15 20:49
Is the drone disconnecting from the controller, or is the message coming up for no reason? If the drone is disconnecting or you are having signal issues, try putting it in 5.8 gigahertz instead of 2.4. This will help with signal interference.

Thanks for reply.
The app tell that Aircraft not connected to RC, so i assume that it is the case, log in Airdata tells that Downlink data connection was lost for 5.4 seconds.
RC is set to auto 5,8/2,4 Ghz. - When I flew yesterday I had no problems, it may be because I didn't have my other mobile phone on me and it might have an impact, but I don't know but will try more flights without another mobile phone with me.

Hi BWJ, thank you for reaching DJI Forum regarding the concern. Please be advised that what we can do is to isolate and check. There's a possibility that the area during the time of flight when the issue occurs, has an active interference. I would kindly suggest trying to fly it to a different location or change the frequency to 5.8Ghz. In addition, we recommend for you to kindly follow the optimal transmission zone on adjusting the antennas of the remote. If the issue occurs or persists, kindly reach us back and provide us the current firmware version and a screen recording showing the concern, thank you.

I soon do some testing, to see if my other cell phone in pocket with me, by any chance have any influence (with and without Bluetooth and wi-fi engaged)  

I am experiencing this with my Mini 2 every time I fly. I wait for the satellites but get a Weak Signal adjust antennas message followed quickly by Aircraft not connected to RC and I can't move the Mini 2. This lasts for around 10 seconds, then RTH initiates and I get the control back.
This is with the Mini 2 a meter away from me.

I am usually flying from my garden but because of this problem I am reluctant to fly it. Everything updated to latest versions.

Now I have made 15 test flights, out of the 5 where I brought my second phone, I could experience these errors with weak signal, all other flights at the same location without phone, or phone turned off, gave no fault at all.conclusion must be that some mobile phones can interfere with the signal to some extent.