Thanks, It seems HUAWEI E3372 LTE USB modem it is not supported. I checked the compatible modem's list and I guess most of them are discontinued As TL-MR3020 was useless for me, I finally returned it.

@DanielTheFreak Hello Unfortunately, I have the same problem. Did you fix it at the end? Did you get any support? Thanks

Hello, My TL-MR3020 is unable to identify the 4G modem that I plugged in. It is requiring me to upload a new configuration file for the 4G modem, which is a common HUAWEI E3372 LTE USB stick. This...