I've been messing with this for over a week now and this has been beyond annoying, so official DJI help would be great.

Been trying to update to the latest firmware version, but literally can't.

Tried using the app...Mavic eventually shuts off during the update.

DJI Assistant refuses to go on my Mac, let alone my Mavic won't even connect to my Mac.

Any solutions to this and sending it in really isn't an option.

Hey there, has the Mavic battery been fully charged when you update the firmware via DJI GO 4? I'd suggest to restart and recharge to see whether the issue remains. Regarding the DJI Assistant 2, please download it from Mavic page and reinstall to see whether it helps.