TTT "Preparing" at 5 minutes

Sometimes, for some unknown reasons the preparing time on our TTT server counts down as normally, then it resets itself back up to 5 minutes. To fix this, I have to restart the server until it works again. Any idea on why it’s doing this?

Does this happen with no addons?

I haven’t tested without addons. Now that you mention it, it probably has something to do with an addon. I’ll have to check them one by one.

Edit: I’m pretty sure I know what addon it is. I’ve mentioned it in the addon’s page. I’ve gotten no reply from the owner of it though.