Unironically try turning your computer off and on again.
Tmux settings are global and persistent. Just deleting your config files is insufficient. You have to kill the server and restart it. Uninstalling and reinstalling will not kill a running tmux server. tmux kill-server
should work too.
Now if it persists across reboots, then there must be a file still lingering somewhere. If you are sure your home directory is clean you can try searching whatever you installed in /etc.
This is all assuming you're trying to go back to a clean slate and failing. If the borked status bar is the result of your current .tmux.conf
, then you'll have to post that.