Hi,
Verizon and other mobile carriers often use carrier-grade NAT, which hides the real public IP behind a shared IP, and this can interfere with VPN performance, path selection, and latency-based routing as the MX may not get accurate uplink telemetry.
But it would be interesting to contact support to confirm this.
I am not a Cisco Meraki employee. My suggestions are based on documentation of Meraki best practices and day-to-day experience.
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