node B service down after change port tag from access to hybrid

one node B is connected to OSN 500 slot EFS8 port 1 for Data service, the port type is Access with default VLAN x, and this port is assigned to ELAN service VCTrunk1 type access default vlan also x.
customer want to add a vlan 1xx in the port of nodeB with IP adsress connected to OSN500 and try to ping this
IP from the RNC:

the 3G team configure in nodeB the Vlan 1xx with the IP,for transmission part we enter to interface managment of EFS8 and we change the port 1 from access to hybrid:

we also change in ELAN service configuration the VCTRUNK PORT from access to Hybrid:

after that Customer inform us that the data service “without vlan” is down and also the ping for VLAN 1xx is fail.

no alarm

after change port 1 from access to hybrid we should change also default vlan from y to x and service for Data became ok
for VLAN 1xx, we add it in VLan filtering and service the ping test succeed:

the Node B data service”without vlan ” is down after we change the EFS8 port 1 to hybrid and also the VCTrunk in ELAN to Hybrid, normally the trafic should remain ok for the data service “without vlan”
after invistigation we found that when we change the port of EFS8 from Access default vlan x to hybrid, the default Vlan change automatically to y=> the data access enter the port and tagged with vlan y, after reach the VCTRUNK Hybrid with default vlan x can  not pass “not same Vlan” see abobe picture
after check for Vlan 1xx, we found that in Elan service configuration, we should add Vlan 1xx in Vlan Filtering to all this later pass

if you change the port type for access to hybrid in interface managment and the existing default VLAN is not equal to 1″like 3 in our example“, the default VLAN will change automatically to 1.
So it’s better to change the port type in Elan Ethernet service from access to hybrid, in this case the default Vlan will not change automatically to 1 :