This happens on Firefox/Chrome/Edge for me, even on fresh profiles
Firefox 75.0 (64 bit)
Chrome 88.0.4324.96 (64 bit)
Edge 87.0.664.75 (64 bit)
When I block the cookies for supremacy1914.com it didn't redirect me, but as expected I could not login.
It seems like this only happens to me. Please help!