Change bridge vlan protocol from 802.1q to 802.1ad and packets start dropping

I have a bridge interface (swbridge) with vlan_protocol=802.1q. Sending tagged frame to it. I can see ARP request in Wireshark Successfully (ping request from another device), but when changing vlan_protocol to 802.1ad I can no longer see packets in Wireshark. I've changed the bridge vlan protocol with this command:

sudo bash -c 'echo "0x88a8" > /sys/class/net/swbridge/bridge/vlan_protocol'

# ip -d -j -p link show swbridge

...
                "vlan_filtering": 1,
                "vlan_protocol": "802.1ad",
...

# uname -a
Linux 5.15.71 ...

# bridge vlan
port              vlan-id  
port2             10
swbridge          10

What I am trying to do is adding a double vlan tag to incoming packets, but I've stuck in this step. ### Edit This setup may not be practical, but it is what I want. I want to see QinQ packet (802.1AD) on Client's port2: This setup is tested successfully on GNS3. Cisco device configs:

interface GigabitEthernet1/0/25
 switchport access vlan 10
 switchport mode access
!         
interface GigabitEthernet1/0/26
 switchport trunk allowed vlan 10
 switchport mode trunk
!

MySwitch vlan configs (before I go through why I get no packet):

# bridge vlan
port1             11 PVID Egress Untagged
port2             1 PVID Egress Untagged
                  11
swbridge          1
                  11

As you see we have a bridge (swbridge) that all ports are slave to. I've created a vlan int (with following code), but it didn't work too until I finally found that swbridge with vlan_protocol 802.1ad din't work at all (no packet goes through it).

ip link add link port1 name port1.11 type vlan proto 802.1ad id 11

And also note that I think required modules is present:

# lsmod
Module                  Size  Used by
8021q                  28672  0
...