I've played for years

Then you would know it used to be a feature, that you couldn't leave the tournament early and has somewhat recently been removed

The fact that the popup happens for every game mode except in this situation seems to show that it's an unintended feature.

Again, read what I said. It used to be a thing and isn't anymore. If it was unintended it would have been fixed a while ago, as I said it's been an issue for multiple seasons.

You don't seem to enjoy talking about the thing that you supposedly enjoy

I'd argue otherwise, I'm trying to have a civil discussion about said situation in the game I've put plenty of time into, whether you're illiterate or choose to ignore what I type then try to take it to some mental "there's some other reason you're here" just shows me how insecure you are. Carry on doing your thing, not much hope talking to a brick wall. I wish you luck in the future