Blue tit roostring

Hello All

I have had a Male Blue Tit roosting since Oct/Nov last year, there have been a few box fights since so I can't tell if its the original one that took control, either way, the box has had a roosting Blu Tit every night since

It disappears every morning around 5am and doesn't return until around 8pm.

Any ideas welcome from more experienced watchers than myself!

Thank you in advance