Banner appears on right side of screen and mouse seems to double click automatically.

A banner that is the same as the one on the side of this screen (brown with a hex pattern) appears on the right side of the page while I'm in game. It messes up the resolution of the page. There is a small "x" in the upper right corner that closes it, but it just re-appears after a few clicks on the map. Thoughts of how to fix this? The mouse automatically double clicking when I single click may or may not be related. Thanks in advance.