Links still show "Website under maintenance"

First of all: Thanks a lot for this Plug-In. I just recently got a new website and it was helpful being able to block it from the world while working on it.

Now here’s the problem:

I ended Maintenance-Mode (a friend visited it, plus I entered it on another browser, so it’s definitely turned off). I even uninstalled the Plug-In again, flushed cache as advised. Still linking it in Facebook shows “Website under Maintenance”. Not just on the webbrowser I used, while working on the page, but on another one, as well.

Any suggestions? Thanks in advance

https://wordpress.org/plugins/lj-maintenance-mode/