Hi @nikmagashi , Its hit and miss as to which dongles will work with the MX's. With the release of the MG's you can see where the focus for cellular failover is/has gone.
Darren OConnor | doconnor@resalire.co.uk
https://www.linkedin.com/in/darrenoconnor/
I'm not an employee of Cisco/Meraki. My posts are based on Meraki best practice and what has worked for me in the field.