EM7455 stuck with no tty nor cdc-wdm devices

I got a EM7455 on an M2 adapter in a housing, and managed to update it with SWI9X30C_02.38.00.00.cwe and SWI9X30C_02.38.00.00_GENERIC_002.082_000.nvu. Initially it was showing this:

DW5811e Snapdragon™ X7 LTE 
APP : 81B6 
BOOT: 81B5 
DW5811e Snapdragon™ X7 LTE 
PRI Part Number: 9907260 
Revision: 001.000 
Customer: Dell 
Carrier PRI: 9999999_9904609_SWI9X30C_02.38.00.00_00_GENERIC_0AT+GMI 
Sierra Wireless, Incorporated 

Then ran

AT!USBPRODUCT="Dell Wireless 5811e Gobi(TM)4G LTE Mobile Broadband Card"

Did not run AT!RESET. Now when the device is connected over USB, it doesn’t create any TTY or CDC interfaces, and this is only printed in dmesg:

usb 1-3: new high-speed USB device number 19 using xhci_hcd
usb 1-3: config 1 has an invalid interface number: 8 but max is 3
usb 1-3: config 1 has no interface number 1
usb 1-3: New USB device found, idVendor=1199, idProduct=81b6, bcdDevice= 0.06
usb 1-3: New USB device strings: Mfr=1, Product=2, SerialNumber=3
usb 1-3: Product: EM7455
usb 1-3: Manufacturer: Sierra Wireless, Incorporated
usb 1-3: SerialNumber: LFXXXXXXXXXXXXXX

Ubuntu 22.04, kernel 6.1, the Gobi DKMS drivers do not compile for me. Is there anything I can do to make the card reset to a default profile?

see if this helps:

Thanks for the hint, but alas - tried a few different driver versions under WIn10, and always getting an unrecognized device em7455 (actually 4 of them). Also, none of the generic windows drivers was accepting a parameter of DisableUsbCompAutoUpdate. Maybe it’s just Windows disliking me, or I’ve spent too long away from it. I guess I might be tossing that one in the bin.

Boot your Ubuntu 22.04. Don’t mess with any out-of-tree drivers. Just load option, configure it to handle the weird VID/PID you’ve got, connect to the correct /dev/ttyUSBx device and fixup the AT!USBPID and AT!USBVID mess.

Something along

modprobe option
echo 1199 81b6 > /sys/bus/usb-serial/drivers/option1/new_id
minicom /dev/ttyUSB3

Note that the AT speaking serial port could be on any of the /dev/ttyUSBx devices. You’ll just have to try them until you hit the right one.

Make sure you choose a valid VID+PID combination this time…