I suspected something list this, so these always scared me.
Actually, magic always scares me. I was putting together an LTE internet gateway from a Mikrotik device flashed with OpenWRT and was confused about how the SIM card slot on the main board interacts with a mini PCIe LTE modem. I looked at the mini PCIe pinouts and discovered the modem is actually USB (mini PCIe has pins for this) and mini PCIe has pins that are wired to the SIM card. I later ran into an issue where the card wouldn't work, but if I tape over the USB3 pins, it would drop to USB2 (still enough bandwidth for LTE) and work.
Actually, magic always scares me. I was putting together an LTE internet gateway from a Mikrotik device flashed with OpenWRT and was confused about how the SIM card slot on the main board interacts with a mini PCIe LTE modem. I looked at the mini PCIe pinouts and discovered the modem is actually USB (mini PCIe has pins for this) and mini PCIe has pins that are wired to the SIM card. I later ran into an issue where the card wouldn't work, but if I tape over the USB3 pins, it would drop to USB2 (still enough bandwidth for LTE) and work.