iPLD300 Incoming CO call not through to another ioPLDK300 connected via Net-CO

[rafiqnextech]

Hi,
We are using 4 iPLDK300 system with interconnect by VoIBE card and config are as bellow
Net-CO Numbering plan:
Site-A Station# 1xxx
Site-B Station# 2xxx
Site-c Station# 3xxx
Site-D Station# 4xxx
Now all the sites can dial directly by dialing station number.
Here Site-1 has CO lines and all net user using this trunk for both incoming and outgoing.

Site-a has AAIB card and all incoming call routed by greeting message.
Now problem is incoming call can't land on site-A only and all other site is ok
Please note that, Site-a to site-B station call is working, only when incoming caller getting message then caller if dial 2XXX then call can't terminated but if dial 1XXX or 3XXX or 4XXX then ok.

Checked the Net-CO config and CO-CO call termination with other end and looks same.
Please assist the probable fault location.

Thanks

//Rafiq