If i use grouping/groups in a forum and i use "auto subscription" or "force subscription" i would expect that when i post something to group A that only group A is the subscriber. Unfortunately are "all" groups including "all" teachers subscribers. Alternatively i have to "disable subscription" and nobody is getting and e-mail about that post

This issue is related/ a update to issues https://tracker.moodle.org/browse/MDL-28058; https://tracker.moodle.org/browse/MDL-31648; https://tracker.moodle.org/browse/MDL-36460

1. Create Groups A, B, and C with at least 1 user in each.
2. Create Grouping ABC comprised of Groups A and B and C.
3. Create a forum with subscription (either "forced" or "auto")
4. Set Group mode to "seperate groups" and "available to group members only"
5. Set Grouping to "ABC"
6. Make a post on the forum to group A

Result:
7. All forum members (inkluding members in group B and C)are getting the post as e-mail

Expected result:
8. Only members in group A are getting the teachers post as a e-mail