DHCP/VLAN abnormalities on T4X compared to T21P

[JAmatller]

Hi,

I have the same problem with T42G.
All of them has 29.72.0.55 firmware and works OK in our LAN (172.1.x.x) with DHCP and autoprovisioning and without VLANs
But now I need to move all of them to a VLAN120.

When reboot, a 172.1.2.x IP address was given from LAN DHCP, also a url for provisioning: http://172.1.1.106/autop
This autop activates VLAN120 and gives SIP Account login info:
network.vlan.internet_port_enable = 1
network.vlan.internet_port_vid = 120

With this info, phone reboots again and a VLAN120 DHCP was found, and a new IP was given (172.16.1.100) even new url for provisioning intpo VLAN: http://172.16.1.1/autop
On this new url I have SIP Account login info.
And i can see url access to this VLAN Asterisk server

But... in few seconds it fails and reboot.
This time with LAN IP (172.1.2.x) but keeps VLAN120 enabled. ... It doesn't work!