Are you trying to apply this on the WAN link or an SSID?
If it is on the WAN link, is this going out to the Internet (looks like it based on the IP information), or over a VPN tunnel?
Unless I'm not awake yet and my brain isn't fully functional, marking traffic to the Internet is useless as it doesn't honor QoS markings. However traffic over a VPN tunnel will be honored by the MX.
I see you have Priority set to high, which is really the only thing you can do (that I can think of). This applies to upload traffic only, so make sure you have the bandwidth slider on the traffic shaping page for upload speeds set accordingly.
https://documentation.meraki.com/MX/Firewall_and_Traffic_Shaping/Traffic_Shaping_Settings