Weird issue on linux server when using teensy 4.1 (serial device) - programing ok, receiveing serial from teensy ok, sending serial to teensy not ok. wierd

Hi

So I'm getting this weird issue in a raspberrypi with virtualhere server where when connectin a teensy 4.1 (arduino similar device) I can receive data on a virtualhere client (windows 10) but not send any serial data to the remote device (The teensy 4.1) Programming the teenys remotely work great, though this is done in programming mode (i guess in a different USB driver/mode?) 

I've tried mani options. Currently 2 different raspberrypies (version 1 and version 3 B+) various OSes, dietpi, raspbian... and all have the same weird issue.

Also tried the virtual here hub on a raspberry py, same issue there.

(update) Tried on a android phone and also same issue

Tried with an arduino UNO, and this works correctly.

Tried the teensy locally on the raspberrypi and there I can correctly receive and send data to the teensy, no problem.

Also and curiously, the teensy 4.1 works correctly on a virtualhere server running on windows 10, so this issue seems to happen only on linux servers.

I'm out of ideas, and I would love to see this working as I need it for several installations. Any help will be apreciated