Unfortunately I wont be around this weekend to troubleshoot this, but I will do that when I return.
A couple things you can try in the meantime:
- 15 minutes is a long time. If the server restarts or the plugin is reloaded at any point during that timer, then the timer will be lost and it will instantly grant the protection.
- That being said, I would recommend trying a smaller amount of time first, like 10 seconds, just to see if that works. That info may help me figure out the problem faster when I return.
- (optional) to provide even more info, you could enable logging in the config and take note of the ID of a tc and send me the log file of that TC. You should be able to see in the log file when the timer has started and when it completes ( and should tell you the reason why). There's instructions on logging in the plugin doc.