Official comment
Is the video feed coming back up after the battery swap?
We added the image location dot cleanup as part of a CPU optimization to help things work better on old devices. Basically if it detects that the camera is falling behind the commands it attempts to free things up by temporarily getting rid of features that are getting drawn and using up resources unnecessarily.
The upload and start button (flight control slide out menu) won't come up until the GPS location is gotten again. This can take some time. You have to wait until the red triangle shows up again.
If there is an issue it is safe to close the app and reopen it as your progress is saved and you can pick up where you left off.