Deleting a scheduled task in another tenant causes a 500 error instead of 401

[ElanHasson]

Describe the bug

If you attempt to delete a scheduled task belonging to a different user, a 500 Error is returned.

Steps to reproduce

1. Create scheduled task as User A
2. Delete scheduled task as user B

Expected behaviour

A 401 Error should be returned.

[joshuaauerbachwatson]

I am currently sometimes seeing 500 errors (instead of success) when deleting scheduled tasks. I am quite sure there is no change of user identity between creation and deletion. Possibly relevant: the interval between creation and deletion is shortish (a minute or two) and the scheduled task is enabled and firing every minute meanwhile. If the deletion request is then repeated, it succeeds.

I don't know whether this is related to this issue or not (strictly speaking it is not, based on the title of the issue) but I thought I'd report it here since it could be related.

[ElanHasson]

Will look into this as part of this item as well.