As some of you might know, i'm a new owner of a DJI Mini 2, and my mobile phone is a Samsung S21 Ultra 5G.
This solution has worked for me so don't blame me if you couldn't solve it this way ... I'm still waiting for DJI issue fix as wel.

I did not yet had a decent flight with my new drone because of some issues with the app DJI Fly.
At first i had two different problems that is common with Samsung owners.

Live feed with black screen - To this problem (at least for me) DJI has fixed it with the new version. Just download the app directly from DJI website and the problem is solved.

App crash - So ... After a long talk by e-mail with DJI support (i'm still on conversation with them by the way...), and problem still remaining i guess i have discover a simple homemade way to solve my problem of app crash.
As i has told you before in differents threads, i can only use the app one time. After i close it, on the second time when i try to run it, the app just crash without any error... The only way i can run it again is after uninstall it and install it again as fresh new.

First i thought it was android that block somehow the app after i close it and try to force it to run in background allways... But that did not do the trick, so i have another ideia.
I notice a time ago that if i try to take off the drone with home wifi connected to my mobile phone, i couldn't and had problems, so i try to run the app without any kind of network...
No wifi, no gps, no 3g, nothing.... Just shut off mobile data and wifi and the app just start normally.



After that, just activate again mobile data so you can have gps.

Don't ask me why... In my case, it has done the trick... But this can't be permanent. DJI has to do something to fix this problem and Samsung owners.
At this moment it has pass too much time for me to return the drone but i'm not happy with my purchase until now!
I do not have other phone (at least one of the recommended ones) and i did not got expensive phone and expensive drone to go around some corners and "hack" drone and app problems so i can enjoy my purchase.
Even if this worked for you, contact support anyway so they realise it is a real problem and there is more than one person with this kind of issues!

For me has done the trick.
Try it yourself even if you have never could start the app.
Hope i could help someone.

Thanks for the suggestion. Unfortunately it does not help me. I've got a S21 and a Spark drone. Had a different phone in the past, but it got smashed s had to get the S21. Tried the trick you suggest above, but no luck the app will not even start.