SL2100 Extensions overflowing to other extensions

[imperium1]

Hello, the customer i have has an SL2100 with 5 analog CO lines. The lines are configured as DIL where in in each mode they ring a different virtual extension which is forwarded to voicemail. This is so each mode can be answered by a message tailored to each time mode (Ext 250:day, Ext 251:night, Ext 252:lunch, Ext 253:break). They are manually changing the modes by a button on the receptionist phone.
In These messages, they are given the options of press 1 for ext 101 and press 3 for extension 103.
What they want is that when a customer presses 1 or 3 it rings the specific extension, but if that extension is busy, it rings other extensions so the call can still be answered.

I set it up so that there is a department group (3100) that contains the 3 reception phones (101,102, 103), and set the forwarding on the extensions that if they are busy to forward the call to the group.
When i first tested it by pressing 3, it rang only extension 103. while talking to 103, i called in from another phone and pressed three, and the receptionist at ext 102 answered the call.
Now they are telling me that the 2nd caller is not ringing the other phones.

what could be the reason for the failed forwarding, or does anyone know a better way to do this?
I am following up another persons programming, and trying to make minimal changes to the way they are setup.

 

[CoralTech]

Anyone in a dept group cannot have any feature active otherwise it won't work. Better off using VE real or not with delay ringing. Dept groups are VERY limited.