I just moved one of these. I'd never seen one before but with the manual I'm doing ok. I'm here grazing for solutions to potential problems before I "FIND" them.

But back to you....

Just venturing a guess but I've had conflicts with the VM answer timer being longer than the call transfer return timer sending the call back without the station ID info on OTHER systems. VM doesn't know where the call came from.

Good luck.

I'll come back after one of the better techs here gives a better assessment.

Experience IS knowledge
All the rest is just information.