I use Android and mine did the same. Was not confident it updated correctly, so used DJI Assistant, whick took 5 minutes for each item Mavic, RC & Goggles.
I think my problem is I have to power off and on my Tab S2 before the G04 app connects to the RC. When its updating, the RC reboots and I think it then fails to reconnect at around 99%. Killing the Go4 program to get out.
In future only going to use Assistant, to make sure update was completed 100%.
Sounds about right for half the people. Something is just not right in the update system. It gets to 99% then finishes but in many cases it does not report back to the software that it has finished.