in 'window->settings/preferences->preferences there is a part about Display->polygons
maybe you find something there that's not normal. Or you could try restore default settings from the Edit menu.
hope this helps you.
<a href="https://www.d2lodshop.com" rel="noopener noreferrer nofollow" class="giveMeEllipsisa" target="blank">D2lodshop</a>
<a href="https://www.gatcity.com/forum/forumdisplay.php?f=3" rel="noopener noreferrer nofollow" class="giveMeEllipsisa" target="blank">GAT City</a>
<a href="https://www.rhymbox.com" rel="noopener noreferrer nofollow" class="giveMeEllipsisa" target="blank">XMPP instant messaging</a>