RB850Gx2 VLAN interface not work after update to 7.1.2

hi,

i have a new RB850Gx2 and have an issue during the setup.
after investigation i can reproduce my error with a really simple setup.

i install a fresh 6.49.3 und configure a VLAN IF on ether5 and then create an IP address on the VLAN IF.

/interface vlan
add interface=ether5 name=test-vlan vlan-id=10
/ip address
add address=192.168.110.40/24 interface=test-vlan network=192.168.110.0

i can reach the IP through SSH and ping, so everything works normal.

then i upgrade to 7.1.2 and the setup is converted correctly, but the system is now only reachable via ping and not responds to ssh.
i have checked via torch and sniffer and the router self gives the SYN ACK back but at the switch no answer packet is reached.
my conclusion is the switch chip does not forward the answer packet.

has anyone an idea to fix this?

regards