So I just discovered that my webhost uses frames for the alias of one of my domain names. So if you visit the alias of the domain, you get to see the original website, but at the URL of the alias. Like this
<HTML>
<HEAD>
<TITLE>domain.com</TITLE>
</HEAD>
<FRAMESET ROWS="*,0">
<FRAME SRC="http://www.thelongdomainname.com/" NORESIZE>
<NOFRAMES>
Your browser does not support frames.
</NOFRAMES>
</FRAMESET>
</HTML>
The thelongdomainname is the original existing website. The new domain should be an alias (and redirected) to the thelongdomainname.
Why is the webhost using frames? Seems very wrong to me
That is utterly wrong. You should contact your webhost and ask them to set it up as a proper redirect. If they won’t do that, I would look for an alternative host.