I haven't added port 80 anywhere, I didn't check to see if it was in URL but I have no idea why it would be. It just appeared in the installer (and I have seen this happen before, on a version of v11 from 2023 which is when I last had a look at it). I do have https enabled. This install is on proper hosting, not local. Last time I ran into this removing port 80 from the installer didn't work as Composr was still trying to use it. Removing it this time seems to have worked but I'm not sure why it was there.
When you ran the installer, were you using a URL that explicitly defined port 80 in it?
Do you have HTTPS?