Full Screen acting strange

In the upper right corner of the map there is a full screen button. When I press this the map goes full screen for brief moment and the reverts to normal view. I am using the map component from a meny item in Joomla. I do not know if this is a Google bug or if the CSS of GMapFP is acting up. I am on Joomla 3.x

malselvhistorielag.no/index.php/kart

Tried to full screen i Edge and in Chrome. Just goes to full screen and then back to normal view. Strange.

By the way this acts the same in the module setup page where you have that map and the option to center.