It was on my work PC behind a company Proxy/VPN so it might play a role in authentification management. (But it sounds pretty crazy/unsafe to have a proxy doing so)
But it could also be just a page loading issue where some poster username was display at the wrong place while the page was loading, I haven’t checked the CSS/HTML
That’s what I would most likely think, looks like the most reasonable option, but had a doubt for a second so thought it was worth asking