After many years working with USB modems, pick a manufacture. We use DS product mixed results. We keep a couple Sierra Wireless and Novatel older USB modems, swap out sims when things get a bit odd and isolate it to a manufacture.
One example. DS wasn’t working properly, so we switch to a Verizon USB Novatel USB modem. Sierra wireless has seemed to work the best for us.
Well since Novatel pushed a firmware update, it didn’t work with Meraki. Then Verizon BGCO got wind of it and started to scramble, and then Apple blocked the USB modem from all Apple products because of security vulnerabilities. Nice chain of events. And it took Novatel over a year to step up to the plate.
I would personally reach out to the current owner of the DS product line and see if they have any resolution. Then reach out to Meraki to confirm the firmware will work with whichever device you want to use it on.
Over the years this has not been as easy as one would think. You might want to hit your head up against the wall at times but reach out. You’re not alone in this USB modem adventure.