Brought this up last May with no replies so I'm doing it again! (thought the
latest client version would fix it) currently running GW8 SP2 HP2 clients
and server.

Assign an user to admin a system distribution list, when they go into
details of it, they have an add button and can select new members, they
click save and afterwards, the changes they made are not saved.

Of course editing the distribution list from C1 works but I kinda liked
being able let select users update distribution list since it worked in past
versions (straight up V8.0.0 I believe).