Hello there, new too to the mavic family.
So what happened so far:
Updated the flight zones, no issues, updated the controller, no issues.
Firmware update of the drone, same as others went to 30% then stuck, the remote had its battery depleted, as soon as it died, the phone started to tell me that progress was going to 99% then it told me that it lost the connection. The drone was still searching for the remote and I was trying to recharge the remote while the phone is plugged in, but of course the remote won't turn on if it's low battery...
So I decided to turn off the drone and use the assistant, it did the first firmware upgrade no sweat, after doing the second I could connect myself to the drone no problems, but no WiFi only because my phone is an idiot, but the remote option was fine.
Now charging since the weather is fine for an initial flight.
EDIT:
So no issues afterwards, I was able to upgrade all batteries and get it to fly no sweat. I would recommend for anyone attempting it the first time to do it with the assistant instead of doing it with the app.