Does this quote from the docs help:
Polling from Outside the Network
By default, Meraki devices cannot be polled via SNMP from outside the local IP network. However, after setting up the community string, an MX can be configured to allow polling from a remote IP whitelist, configured under Organization > Configure > Settings > SNMP.
Source: https://documentation.meraki.com/zGeneral_Administration/Monitoring_and_Reporting/SNMP_Overview_and_...
