Possible attendance inconsistency with non-student user enrolled in class as "Student"

Hello,
I found a possible inconsistency in Attendance.
I enrolled a teacher/staff user in a class with local class role Student.
Then I took class attendance and marked this person Absent.
Later, I deleted all attendance records from Attendance by Person.
Everything looked clean there, but in Attendance Trends I still had one mysterious absence when selecting All in the Form Group filter.
After checking the database, I found that this remaining log belonged to the teacher/staff user who had been added to the class as local role Student.
So it seems:
class attendance accepts this user because of the local role
but Attendance by Person and some other screens do not treat this person as a normal student
which can leave an attendance log visible in reports but difficult to remove in the UI
This looks like an inconsistency between:
class membership with role Student
and “real students” available in person-based attendance tools
Maybe Gibbon should either block this case, or handle it consistently across attendance screens.
Has anyone else encountered this?