Using Clean_up with pfUI, pretty often after sorting bags I got some items locked up until some time passed or relog.
Not sure which addon this issue is exactly, gonna report to pfUI as well.

Oh, I see now. Thanks, voted. Any change to add delay in sorting for now until bug has fixed?

don't, just upvote here: https://elysium-project.org/bugtracker/issue/966

It seems even with a quite significant delay it still happens. Not sure what's causing it exactly.