It looks all ok on the "Add or Remove Gear" page. I can select or deselect any gear without problem. The problem is that changes are not saved correctly.
I have four gear pieces defined, two of them are added to cycling activities automatically. I want to add a third one manually, so I open "Add or Remove Gear", select/tick that gear on the list then I go back to activity screen (pressing top left back arrow). There should be three gear pieces added to activity now but one of the already selected gear is somehow disconnected from that activity, as if deselected it on the "Add or Remove Gear" screen (which I didn't). When I go back to that page and try to select it back, some other gear piece(s) got deselected.
It only happens in Garmin Connect Mobile Android app, it works ok in Garmin Connect Web app. In fact, the only way to correct gear associated with activity is to do it in the web browser. "Add or Remove Gear" page in GCMA is dead for me now.
It used to work mid June, but it is broken now.