This is most likely a platform issue and therefore completely independent of both Linux and the 7455. The modem will enumerate in some way if it is powered and connected to the USB bus. You should check that.
Depending on the configuration of the modem, you may also have to make sure pin #20 is high or not connected.
The MC7455 USB3 SS support can also cause problems in laptop slots with PCIe. You should disable PCIe in the slot and/or modem, or simply cover the pins with tape. See e.g https://techship.com/faq/minipcie-based-cellular-modules-supporting-usb3-are-not-detected-in-the-host-system/ for instructions.
And finally: Many laptop vendors will whitelist supported wifi and wwan modules. Using a different modem will result in a POST error. But YMMV. Maybe your laptop disables the slot instead.