I unfortunately have the exact same issue, and I wonder whether I should return the device or do a software fix ?
I have nothing connected to USB and use the official charger. Wifi 2Ghz is on but that really shouldn' t be an influence as mentioned above.
I've sent this question to quectel But they were slow to deal with it Please wait a few days I will update this post if there is any progress I'm sorry for the inconvenience