I use I'm Watching all the time.
If I don't post, I click 'watch this thread'
Increasingly, threads I have continually posted on are not in I'm watching. I have to go into 'I'm on, and occasionally they are not there either.
It happened just the odd time, but it's now got to the stage it's hit and miss whether threads I've been posting on are there or not.
Laptop, Google chrome