David,
Both claim not to have unsubscribed, and there is nothing in the
Activity log to show them unsubscribing.
There shouldn't be a circumstance where a member leaves or is removed from a group or subgroup without that action being logged in the group or subgroup. So that's something I'd report to [email protected]
As is often the case, writing up a bug report makes you look at seemingly-unrelated things. It turns out to be a timing issue and a facet of being a moderator. A moderator of a main group can send messages to a subgroup they are not a member of, so it might appear they are a member, but not really.
We learn something new very day..... :-)
Cheers
David
