So i have a phantom 4 and since i upgraded the firmware on it, my live stream doesnt work anymore and the sd card slot doesnt work anymore, iv put the sd card out, try to format it, put a new one in and it doesnt work, I tryed to downgrade the firmware a million time, and it freeze at 55 pourcent, and shuts down.

I have then bought another drone, dji mavic air 2. and now this guy wont connect to my phone (i have samsung s20 ultra) i also have tryed another old phone, no results,
I did try with other cables still nothing.

I use those drones for work.

can someone help me out here ?  i dont know what to try anymore
.

Hi there, sorry for any inconvenience caused. For the phantom 4 issue, could you please tell us the firmware version you upgraded? Please refresh the firmware of the drone and the remote control to the latest version to see if the problem still exists. And please also pair the drone to the controller again for a test.
For the Mavic Air 2 issue, could you please tell us your phones' model and operating system version? And please upgrade the app to the latest version to see if it works.