After a ride, Garmin Edge 530 doesn't allow end and save the ride. Activity Start / Stop button beeps on pressing, but doesn't actually do anything. Pressing the power button brings the following message:
Connect IQ app is open
Close the app before putting the device to sleep or powering off.
This seems to be a bug introduced in 7.00 Garmin Edge firmware. This happens if a course was launched from a Connect IQ app (Strava Routes, Komoot, etc.) I'm sure Garmin will fix this, but for now, a workaround is pretty simple - power off the Garmin Edge by pressing and holding the power button until it shuts down (this will kill the offending Connect IQ app). Then power it back on and activity Start / Stop button will work as expected allowing you to end and save the activity.
Garmin Edge 530 (Firmware 7.00)