I have a customer that has an MICS with 5.0 SW with PRI and about 75-80 users. Customer is saying that as calls come in and are parked, as calls are picked up, the remaining parked calls shift for example from 102 to 101. I called customer and we tested it and it seems this scenario is happening. Any ideas? Below is their email to me.

Sometimes line 101 & 102 will ring in at the same time. She will answer 101 and no one is there. She will then answer 102 and it is the same phone number on ID from 101, that line (102 ) is the one the incoming call is on.

When more than one line is on hold, as someone else picks up 101, or the person hangs up on 101, each line still on hold moves up. So if 101, 102 & 103 are all on hold and someone else picks up 101 or they hang up, 102 will become 101 and 103 will become 102. This causes a lot of confusion on both her end and others trying to pick up the line that was on hold for them.