That does sound frustrating, and I have another experiment for you – if you reboot the phone will it allow you to reconnect to the meter? If it’s the “phantom connection” issue then the phone is maintaining a connection to the meter but not giving access to the connection to the app – rebooting either end of the connection should fix it.
If rebooting the phone fixes the issue as well, you can be pretty sure it’s the phantom connection issue. It may also be possible to work around this by setting your phone to airplane mode, then setting it back, forcing a disconnection.
Hope this helps, best