@ggatten i ran into the same problem and just resolved it. I have a meraki MX105.    Solution: As per Meraki Team we can't disable the port randomization firewall/NAT but instead define a firewall/NAT port Session Persistence. Once a port is assigned to a session, that port will remain mapped to the session until the session is terminated or times out. During the life of the session, the port will not change, ensuring that the external service communicates with the same source port throughout. Achieved NAT A and B Nintendo switch perfectly working now. 9-26-2024 11:10. It took me a while to work with meraki support for almost 2hours   P.S this feature can be configured from the backend. So, you need to open a case with meraki support, and they will help you out. Only few individuals Meraki tech has knowledge on this as this is something new in their environment. ... View more