bridge setting with vlan service tag and QinQ

Hi Guys

I have a service tag vlan 20 and it has 4 sub vlans 100,200,300,400 (all these 4 vlan without service tag checked and configured to use vlan 20 as parent)

vlan 20 with service tag parent is eth1

eth2 is where the cisco router would be connected and the cisco device is configured with vlan 100,200,300,400

On the Mikrotik

Do i bridge eth2 with the sub vlans 100,200,300,400? (i have tried this and it causes packet loss)
Do i bridge ethr with vlan20? (I have tried this and traffic not passing)

May I know what i did was wrong?

Thanks!