ACX5448 EVPN instance configured with "vlan-id none" not working for vlan normalization in interfaces with dual-tags

When "vlan-id none" is configured in an EVPN routing-instance, the interfaces in the routing-instance that only have a single tag normalize their vlans without issue.

When we add in an interface with dual-tags, then one of the tags is preserved when it's sent across the evpn to an interface with a single tag.

routing-instances {

  Test {

    protocols {

      evpn {

        interface xe-0/0/0.2510;

      }

    }

    instance-type evpn;

    vlan-id none;

interfaces {

  xe-0/0/0 {

    unit 2510 {

      encapsulation vlan-bridge;

      vlan-tags outer 2510 inner 2510;

    }

This kills communication between the networks on the two interfaces.

When the customer configures "vlan-id" under the routing-instance instead of "vlan-id none" the issue is fixed.

This issue sounds like the one described in the following PR.

The ARP request packets might be sent out from ACX router without VLAN header

https://prsearch.juniper.net/problemreport/PR1638421