After the newest update during climbing on an artificial wall, the app did not register changes in altitude. As a result, the watch did not automatically detect the start or end of the climb.
Sorry, a little bit of topic but where did you find the climbing activity?
It is called Climb Indoor -> www8.garmin.com/.../GUID-D67857E8-04FB-44CA-9D58-B77AB8D50F83.html