Try:
set firewall modify CLEAR_DSCP default action accept set firewall modify CLEAR_DSCP rule 10 action modify set firewall modify CLEAR_DSCP rule 10 modify dscp 0
and apply to interface
Try:
set firewall modify CLEAR_DSCP default action accept set firewall modify CLEAR_DSCP rule 10 action modify set firewall modify CLEAR_DSCP rule 10 modify dscp 0
and apply to interface