I've never had this issue before. I always upgrade my firmware with DJI Assistant, but for some reason my P4P controller doesn't seem to properly connect to DJI Assistant 2. When plugged in, the device appears but it shows as "Unknown Device" and you 're unable to click on it.

I've tried this on two different computers. Tried Assistant v1.1.8... v1.2.0
Firewall turned off. In device manager it shows as "USB Serial Device (COM3)", attempted right click to update driver and doesn't find anything.

Note: I have the controller without the screen

Mine does the same. I think it updates via the app now which I don't like. I prefer to have it connected to a laptop/computer instead of relying on a phone/pad.

Hard reset your controller. Hold C1,C2, and the photo shutter button and turn it off. When you turn it back on, press c1 c2 and video record, hold until you hear beep-beepbeep.

You can't update the RC with Assistant 2 software. The update is done by just connecting only the RC to your tablet/phone that has a wifi connection.