Run the display qos queue statistics interface interface-type interface-number command to check whether packets enter the correct queues on the outbound interface.
Run the display this command in the interface view on the inbound or outbound interface to check whether the trusted priority type set using the trust command is correct. (If the trust command is not configured, the system trusts the 802.1p priority in the outer VLAN tag by default.)
Run the display this command in the interface view on the inbound or outbound interface to check whether the trust upstream command is configured. If not, the system trusts the DiffServ domain default by default.
Run the display this command in the interface view on the inbound or outbound interface to check whether there are any configurations affecting priority mapping. If so, delete or modify the configuration as required.