The teachers cannot enter grades for personalized accompaniment. Why is this happening, and how can it be resolved?

By default, services for subjects marked as personalized accompaniment have a mode Without grades.

To enable teachers to enter graded tests, go to the display Resources > Subjects >  Services per subject, select the subjects for personalized accompaniment, then all the corresponding services, right-click and choose Modify the selected services > Service's evaluation mode > With grades.