USB Tethering completely unstable

[Electrical-Judgment]

Hello guys, ive an unlimited LTE data plan and im trying to u se it the more i can since is much faster than my home connection, i am using an LTE modem (HUAWEI B535) placed in one room to achieve best LTE signal and im using my phone connected with wifi 5GHz to the modem and with usb to my pc. The normal USB tethering feature is really slow and i cant understand exactly why, also if i try to change driver in Win10 it reaches big speed but the PC crashes with a BSOD very often. If i use apps like PDANET it works perfectly except for a connection crash every like 30mins, that causes my downloads to fail everytime. As phone im using a OnePlus 6, is there anything i can try to at least debug the problem?