I’m having similar Serial UART communication issues on both the Jetson Nano and the Xavier NX.
On the Nano, the data goes both ways but is scrambled / corrupt.
On the Xavier NX, things worked for a while but, since 2 days ago I’m no longer able to send any data from the jetson. I only see incoming data.
As many people facing this problem on all Jetson platforms mayebe NVIDIA could relese a patch or a script which disables any background consoles, login shells or other processes that might be interfering with the UART pins? For example, on the Raspberry-Pi it’s very easy to configure via the raspi-config utility.