I play several games that have an alert pretty consistently. I play the game, set the alert, go off and do stuff. Recently I've noticed that the alert for Crypts keeps not being there. The first couple of times it happened, I thought I must have messed up, but it keeps happening, and specifically with Crypts, not the other alerts.

If the alert consistently didn't work, I would have noticed sooner, but it does work most of the time...just every few days its suddenly not working again. I play the game, set the alert and it seems to work fine, the alert shows up like its supposed to. So I forget about the issue, until a few days later when it fails to show up again.

Desktop PC, Win10, newish FF.