I paid a developer/company to install something to bridge our front page with the forum, so accounts/comments would sync. For that to happen, your forum account (xenforo) automatically creates an account on our main site (wordpress)
I think there's an issue with some accounts being unable to bridge, but its a nuisance to work out what the issue is because it works perfect for me. I'm pretty sure when cookies are cleared, it'll iron out as the system works out your forum account matches the front page.
Anyway, clear cookies and if problem continues screenshots and information on device very useful