We have a ton of customers on MX64 with poor USB Cellular failover, and their LTE signal is fine. It is a known issue with Meraki that they have only addressed in 17.x for MX84 and above. If you haven't had issues with this, it might be because your version is 16.x or below. https://community.meraki.com/t5/Security-SD-WAN/New-MX-17-7-Stable-Release-Candidate-Firmware-huge-number-of/td-p/149834
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