MSTP not working on CRS317

We have a ring with 10 CRS317-1G-16S+/r2 switches on v6.47.9 (factory default)
The switches are alternatingly connected with a single fibre cable and a 802.3ad bond of 2 XS+DA0001 interfaces.
Hardware Offload is enabled/working.

When enabling MSTP, the correct ports are being “blocked” (alternate/not forwarding) per MSTI.
We however see that the VLANs in question are not being blocked at all. Traffic is flowing through the alternate port.

Config snippet:

/interface bridge
add frame-types=admit-only-vlan-tagged ingress-filtering=yes name=CORE priority=0x7000 protocol-mode=mstp region-name=XXX vlan-filtering=yes
/interface bridge msti
add bridge=CORE identifier=11 priority=0x7000 vlan-mapping=3051,3054,3055,3056,3261,3262,3316
/interface bridge port
add bridge=CORE frame-types=admit-only-vlan-tagged ingress-filtering=yes interface=SWITCH_INTERCONNECT
add bridge=CORE frame-types=admit-only-vlan-tagged ingress-filtering=yes interface=sfp-sfpplus10

/interface bridge vlan
add bridge=CORE tagged=SWITCH_INTERCONNECT,sfp-sfpplus9,sfp-sfpplus10 vlan-ids=3316

As expected with our config, sfp-sfpplus10 is an alternate port in MSTI 11. We would expect that this is blocking VLAN 3316, but we are seeing traffic passing on this VLAN.


/interface bridge> monitor 0
                    state: enabled
      current-mac-address: 2C:C8:1B:71:6A:43
              root-bridge: no
           root-bridge-id: 0x4000.48:8F:5A:82:2B:16
  regional-root-bridge-id: 0x4000.48:8F:5A:82:2B:16
           root-path-cost: 0
                root-port: sfp-sfpplus10
               port-count: 5
    designated-port-count: 2
        mst-config-digest: cc9030cbf2e92a2d952a31e20e87283b
             fast-forward: no

/interface bridge port> monitor 2
                 interface: sfp-sfpplus10
                    status: in-bridge
               port-number: 3
                      role: root-port
                 edge-port: no
       edge-port-discovery: yes
       point-to-point-port: yes
              external-fdb: no
              sending-rstp: yes
                  learning: yes
                forwarding: yes
   internal-root-path-cost: 30
         designated-bridge: 0x8000.2C:C8:1B:71:64:51
  designated-internal-cost: 20
    designated-port-number: 1
          hw-offload-group: switch1

/interface bridge msti> monitor 1
                    state: enabled
               identifier: 11
      current-mac-address: 2C:C8:1B:71:6A:43
              root-bridge: no
           root-bridge-id: 0.00:00:00:00:00:00
  regional-root-bridge-id: 0x400B.48:8F:5A:82:2B:16
           root-path-cost: 0
                root-port: SWITCH_INTERCONNECT
               port-count: 5
    designated-port-count: 1

/interface bridge port mst-override> monitor 6
                      port: sfp-sfpplus10
                    status: active
                identifier: 11
                      role: alternate-port
                  learning: no
                forwarding: no
   internal-root-path-cost: 220
         designated-bridge: 0x800B.2C:C8:1B:71:64:51
  designated-internal-cost: 20
    designated-port-number: 1

RESOLVED

After upgrading to 6.49 (and related reboot), the alternate port is now correctly blocking the VLANs.