4G Quectel usb modem super low speed with opnsense

[derbert]

Hello,
I've got the problem that my internet speed is not higher than about 0.1mbit/s DL and 5mbit/s UL when using a Quectel EM160R-GL 4G modem with usb. OPNsense is run in a proxmox vm and the modem is given to opnsense via a usb passthrough. The problem does not arise when the modem is given to a win 10 vm in proxmox via usb passthrough. DL speed is then about 80mbit/s and UL about 30mbit/s.
I don't know why the speed is so low when managed by OPNsense?