This plugin changed devs and went completely downhill.

I installed this plugin back when it was owned by Sandhills. I inadvertently upgraded it from the admin panel and now it’s broken. I needed to make some slight changes in the message to display to non logged in users and it won’t make any. It’s basically stuck. I tried deactivating it, hell, even deleting it. My non-logged-user view is stuck on the same message. This is disappointing and honestly quite worrying, as deleting any other plugin would result in a change, how come this is stuck?