Topics get unwatched

In using questions for about 3 weeks, Everybody watching the 'development' topic has been mass unwatched for some reason about 2-3 times. It happens sporadically and I'm not sure what the cause is (maybe applying updates to Confluence resets everything) but it is annoying to have that list of people go in and click watch on the topic again and they have missed whatever questions were asked in the interim.