The night before yesterday, one of my friends using Open Beta became Trusted User.
At that time, his/her trust rank on the nameplate (shown when we opened Quick Menu) is still Known User.
Everyone (including him/her) in the instance see he/she is Known User on nameplate so the release channel of VRChat (OpenBeta or Live) of others is not related.
Someone joined the instance after he/she became Trusted, but they also see his/her is shown as Known on nameplate.
We see his/her trust rank is Trusted on the menu (in both OB & Live) and on web.
It's too hard to reproduce this on Live so I didn't check if this happens on Live but at the time I became Trusted, trust rank on nameplate became Trusted immediately so I think this is a OpenBeta's bug & reported here.
He/she tried the following at that time:
  • Rejoinning the instance.
  • Changing Appearing as to User and back.
However, the Trust rank of him/her on nameplate was not updated.