Hello!
I would advise you to ensure these this list below is allowed in your network/upstream device.
Please check the firewall information by heading your dashboard ( Help > Firewall information ) to help guide you in creating firewall rules for the Cisco Meraki cloud.
Destination IPs : 199.231.78.0/24, 108.161.147.0/24, 64.62.142.12/32, 209.206.48.0/20
UDP port : 7351,7734
Thank you!