I am also experiencing this issue (we had a small discussion here and I wasn’t the only one experiencing this). Not sure how long this has been going on but probably not always since I’ve managed to win some coins in the past. There also seems to be quite a few different bug reports in github, reddit etc from even a few months ago.
The Chiadog bug on Windows is a great tip. However, altough I am running everything on Windows, the stopping is real. I’ve gone through all the options I could imagine, and I’ve also started to think if this has something to do with new plots joining the farming after completion.