I’m seeing the same issue on a fresh install today. After successfully upgrading the firmware, the app refuses to stop asking me to upgrade the firmware.
Then, if I manage to turn off the firmware upgrade warning, which can only be reached by upgrading the firmware(!), the app spends many seconds initializing… every time I make a connection.
This is on a Moto G4 running Android 6.1
On a Nexus 5X running 7.x, which I first connected after the firmware was upgraded, I don’t have this issue.