Sounds like you are trying to do something the system was not designed to do and that is Transfer or Forward No Answer calls to AA.
Once Night Service is activated the call becomes a Transfer.....i.e. Service Mode answers and transfers to the members programmed immediately, any AA settings will not matter.
Only some systems can a human transfer back to AA using a feature code.
If you record your general message for people to press * to return to Auto Attendant then there is no issue....return to AA must be set to Yes.
Or maybe try to fool it somehow.....
Choose an unused DN
Change Intercoms keys to equal NONE (or 0)
Forward No Answer to vmails DN
Add that DN to your night service.(or overflow hunt group to that DN)
Test
or
Choose an unused DN
Forward No Answer to vmails DN
Build an Info mailbox to match the unused DN.
Record a second of silence.
Add that DN to your night service.
Test
=----(((((((((()----=
curlycord