The VyOS udev rules `/etc/udev/rules.d/90-vyos-serial.rules` for creating persistent names for USB serial interfaces does not match `ttyACM` serial devices. This leads to USB-based serial interfaces using CDC ACM (e.g., ttyACM0) not being registered under `/dev/serial/by-bus/` and therefore not usable as serial console eg: `set system console device usb0b4p1.0`.
The fix is to modify the pattern match both ttyUSB and ttyACM devices:
```
KERNEL!="ttyUSB[0-9]*|ttyACM[0-9]*", GOTO="serial_end"
```
This ensures that both ttyUSB* and ttyACM* serial devices are properly recognised, preventing them from being excluded by udev.
This was accidentally broken in https://github.com/vyos/vyos-1x/commit/fa07bc3b87be142572124a2ce5c077cb42272418
PR Pending.