When a teacher doesn't have accessallgroups capability, it seems the participant count on the assignment screen says the total number of participants, rather than the participants who that teacher has access to.

Replication instructions:

1. As Admin...
2. Create/edit a teacher role without the accessallgroups capability
3. Create a course
4. Enrol two students
5. Create two groups with a single student in each
6. Assign a user as a (non accessallgroups) teacher
7. Add that teacher to one of the groups
8. Create an assignment in separate groups mode
9. As a teacher, visit the assigment. observer that the participant count and then click on the list of submissions and observer the number of submissions

Expected result:

• The teacher should see the same number of participants as is in the summary page (1).

Actual result:

• The teacher can see the total participant count (2) but only one student in the grading screen