ok, next step was to disable all plugins except yours and the CPT UI.
but no luck…

OK, Syam, now i found it.
It was my fault.
I granted my test user with the editor role super admin privileges some time ago and didn’t remember (It’s a multisite setup). Since this extra is not displayed in the edit users screen as long as you visit it with the main super admin user, tis was kind of obscured.

nevermind, i’m glad we found it.

kind regards,
daniel