Hi Rene,
We have just pushed an update for the Grimlock Login plugin. Updating this plugin to the latest version should fix this issue.
After the update, the problem should be fixed. However, you might still be seeing the issue because your browser cache is showing you an older version of the page (browsers do that to load pages faster). To see if the issue is resolved you will need to empty your browser cache and reload the page. If you want to read more on what browser cache is and how to clear it, here is an article that might help you: How to Clear Internet Cache in Every Major Browser.
Kindest regards,