I tried to reproduce the problem myself with an external server and then I cannot reproduce it. So maybe it has something to do with my internal environment or my browser cache.
Another thing I noticed.. I have a virtual server with multiple (sub)domain names, but when i connect to sub1.example.com:80 it redirects me to another domain (the first in the list) for example sub2.example.com:443. For any (sub)domain it always redirects me to the first domain in the configured list.
I would expect that it keeps the domain part as it is.