I wasn’t able to pair my smart trainer or cadence sensor the second time I logged in.
After attempting a lot of things over several days, I decided to uninstall the app, and installed it, again, with little hope that I would succeed.
During the logging in process, I was prompted to turn on the location service. Then I remembered that I was asked to turn on GPS the first time I logged in.
I suggest that you include this promot in the logging in procedure.