My Galaxy watch used to be great at swim tracking. Now on every session it starts dropping lengths (only buzzing to recognise the length on the third length rather than the second as configured). It then decides that I have stopped and activates auto pause. Before it is suggested, no, I am not stopping and (to try any stop the dreaded auto-pause) I am keeping the turn around at the end of each length as uniform as possible. Questions: Why is this happening and does anyone else have the issue and know how to solve it? You can disable auto-pause from running and other Samsung heath monitoring functions - why is this not an option for swimming? It is very, very annoying. I have tried Swim instead of Samsung Health - that has also suffered from auto pause.
Like you, mine worked quite well but I haven't been to the pool since March due to covid. No autopause and buzzed every 10 lengths. I did have watch tracking issues on other activities and performed updates to watch, watch apps, phone and wearable app as well as a watch factory reset with backup. This resolved my other activity tracking problems including open water swim tracks. Try this first.