Do you ever intentionally disable it, or otherwise adjust that setting? I.e. have you messed with that setting *at all* since you set it? Running multiple instances should be fine, but there can be complications if you change preferences in one while the other is running. I get that you're saying it seems to change itself, but it would be helpful to know if you literally never change that setting, or if you do sometimes, but don't think you're doing it *in these particular cases*.
- Oshyan