PySerial not working with Telit modem and Sixfab Base HAT

I have successfully connected via USB TELIT LE910CE to a Jetson Nano with JetPack4.4. After startup, the module is recognized using Linux commands lsusb and dmesg and the 5 USB ports are created correct. I can send AT commands using minicom -D /dev/ttyUSB2 and all is fine.

The problem starts when trying to use some Python code with serial commands, using import serial. These commands usually work fine on USB serial (eg also with UART), but it appears that the python codes do not work after module connection, especially there is no reply from the USB serial port when after sending AT command. It looks as if the kernel driver prevents using USB or is locked on the communication. Again, this is only with Python serial library while minicom terminal usage is fine.

Any idea…?