Only on your website, I am able to reproduce your issue using a fresh install of Microsoft Edge and their discontinued Internet Explorer browser.
I cannot reproduce the issue on UBBCentral, or three of the other UBB.threads forums I've tested.
The issue may be related to a broken custom script or the invalid custom HTML on your forum. One that is breaking everything after it.
Your HTML in your custom top menu around the "Contact" is invalid. It is missing a quote after the url.
This is your code:
<a
href="http://www.oldgas.com/ezform.htm><ACRONYM TITLE="Send Oldgas.com a Message">Contact</ACRONYM></a>
You are also using a script from Ebay. I am not sure how old that is. It may be breaking every JavaScript after it, for Microsoft browsers.
<script>window._epn = {campaign:5336160409};</script>
<script async src="https://epnt.ebay.com/static/epn-smart-tools.js"></script>
Try removing the whole EPN script, and see if that makes a different just on your website.
Microsoft's browsers dont seem to be as forgiving when it comes to invalid JavaScript.
edit:
you also have a bunch of other really old EPN (Ebay) related html and scripts on your pages. you should look at updating to their current code.