Hello, try to setup some simple configuration on RB750G :
Port 2-5 in switch group
Port 5 connect to PC and must be untagged, but on out port (port 3) it must be tagged with vlan-id 7
Port 3 connect to L2 switch and must be tagged.
Try many config, rule and others.. but didnt work, on L2 switch i cant see any tagged packets with vlan-id 7.
When i change RB750G to L2 switch with same config - all work fine