404 on valid gitlab.com URL

I use gitlab free plan and I invited a colleague, who has a ridicilous problem - he cannot confirm his account and he cannot reach the login page over valid URL. Instead he allways gets 404. For example this https://gitlab.com/evopodpora/orwii-web/-/issues/30 produces 404 error on his - screenshot attached. He is the only team member, who has this problem. We have the same provider and are in the same network. Has anybody an idea what this might be?
Thanks a lot!