Different apps have their pros and cons and it is great if you can switch midair without losing connection between controller and drone.
This worked fine last summer assuming you killed the app you left before opening another

This no longer works with the latest fw update for Dji mini 2.
the video feed gets corrupted even if you kill DJI fly app before stating  e.g. Litchi. and vise versa.
The only way that I have found to make the switch work is to turn the controller of and recconnect to the drone.
This  is very risky as the drome may start a RTH and reconnection might fail.

I would like to know what has changed in the communication between controller and drone regarding video feed and if there is a way to mitigate this?
I would hope that this is corrected in the next fw update as different apps have their pros and cons and it is great if you can switch midair.

Dont switch mid flight,  you should land and switch apps.

It is possible that the latest firmware update for your DJI Mini 2 drone and controller has changed the way they communicate with each other. Without knowing the specific changes made in the update, it is difficult to say for certain what is causing the video feed corruption when switching between apps.
One potential solution is to try clearing the cache and data for both the DJI Fly app and Litchi app on your mobile device.

EllinorWilliam Posted at 5-2 20:56
It is possible that the latest firmware update for your DJI Mini 2 drone and controller has changed the way they communicate with each other. Without knowing the specific changes made in the update, it is difficult to say for certain what is causing the video feed corruption when switching between apps.
One potential solution is to try clearing the cache and data for both the DJI Fly app and Litchi app on your mobile device.

I was wrong it was not the firmware - it was the fly app version.
The function works again with latest app release 1.10.1

I use the KillApps android app to kill all apps before switching mid air.

djiuser_r3kudo3YA23G Posted at 5-4 01:36
I was wrong it was not the firmware - it was the fly app version.
The function works again with latest app release 1.10.1

That's great that you have found out the way to the issue.
Well, in my case, I had to address the root cause of the issue by contacting DJI's technical support team to see if they have any solutions or workarounds for this compatibility issue. I thought, they might be able to provide more information on any upcoming firmware updates that may address this problem.
But now I will try by updating the Fly App version to function it.
Thanks for the help, Mate!

mark11111111
Did you get un answer from DJI?