Student's Calendar not picking up new due/closing date group overrides after the student assigned to a different group

Scenario (here: described for Assignment; analogous case applies to Quiz's closing date group overrides):

1. Teacher creates Group A and Group B in the course, assigns Student 1 to Group A.
2. Teacher creates an Assignment (group mode: Separate groups)
3. Teacher adds a group override with different Due dates for Group A and for Group B.
4. Student 1 accesses Moodle and checks their assignment Due date in Dashboard / Timeline, Calendar, Upcoming events block, Assignment page, Course page (due date displayed under the assignment link), etc. - all these places show the same Due date override for Group A - very good.
5. Teacher decides to move Student 1 from Group A to Group B, and does so on the course Participants page, using the Groups column drop-down options.
6. Student 1 - without logging out after Step 4 - views again his/her Moodle Timeline, Calendar, Assignment page, Upcoming events block, to verify the current Due date for the assignment.

Encountered behaviour:

1. Student sees the correct (new) Group B override Due date on:

• Timeline
• the Assignment page; Course page (below assignment link)
• Activities block > Assignments list (if used)

HOWEVER:

2. Student sees NO DATA for the Assignment (and any other affected assignment or quiz with Group B overrides) in

• Calendar (course and dashboard)
• Upcoming events block

3. Student needs to log out of Moodle, and log in again, for his/her Calendar to properly refresh and start showing the new Group B due date override.

EXPECTED behaviour:

After being moved to Group B, Student should immediately see the correct Group B Due date overrides in the Calendar and in the Upcoming events block - without being forced to log out and log in again.

NOTES:

1) This tracker was added following this discussion: https://moodle.org/mod/forum/discuss.php?d=432620 . The issue was first created under a very different title, but I updated it after deeper research.

2) For the record (perhaps to some extent related?): There are other problems with group override due dates displaying incorrectly / inconsistently for teachers - as reported in https://tracker.moodle.org/browse/MDL-74014 (cf. also quiz closing dates: https://tracker.moodle.org/browse/MDL-74015 ).