I've had my Samsung Galaxy Active 2 (40mm) watch for around 18 months now. I've worn it consistently since I bought it, but aside from a swim every now and again, wouldn't say it's especially had much active wear.
Yesterday, however, I discovered that the rear glass cover (in front of the heartrate sensor) had fallen off in my sleep (I discovered it on the floor beside me).
I've seen a couple of similar threads in the US Community, e.g. https://us.community.samsung.com/t5/Galaxy-Watch/Galaxy-watch-active-2-heartrate-sensor-cover-fell-o... and https://us.community.samsung.com/t5/Galaxy-Watch/Galaxy-Watch-sensor-cover-fell-off/td-p/1075781 but didn't find any similar reports in the EU.
Has anyone else experienced this? I've been pretty happy with the product until now, but not impressed by the build quality if it can start falling after less than two years of normal - not especially active - wear.