Yocto linux, C# and console input/output capturing within shell scripts

Question

I am developing a C# application (.net 5) that will run on a embedded linux board based on the yocto linux project.

Everything works perfectly as long as I launch the app manually, I can read inputs, write outputs, etc etc.

My troubles start when I try to launch the application automatically. What i've done is the following:

1. I created a sh script that launches my application, with the following body:

   #! /bin/bash
   STDOUT="/dev/ttymxc0"
   cd ~
   ./controller/Controller < $STDOUT > $STDOUT
   

In order to be able to capture key presses and write outputs I had to redirect both input and oputput to the serial port.

2. I then created a systemd script with the following body:

   [Unit] 
   Description=Controller autolaunch script
   
   [Service]
   Type=simple
   ExecStart=/bin/sh -c '/home/root/controller-start.sh'
   
   [Install]
   WantedBy=multi-user.target
   

Inside my application I use Console.Writeline() and Console.ReadKey() to manage user I/O.

So long:

• Direct execution (aka "run the application from bash") => OK
• execution via sh script => OK
• execution via systemctl start servicename.service => OK
• execution at logintime => FAIL

The application fails with the following exception:

autostart.service - Controller autolaunch script
Loaded: loaded (/lib/systemd/system/autostart.service; enabled; vendor preset: disabled)
Active: failed (Result: exit-code) since Mon 2023-07-31 13:32:25 UTC; 7min ago
Process: 175 ExecStart=/bin/sh -c /home/root/controller-start.sh (code=exited, status=134)
Main PID: 175 (code=exited, status=134)

Jul 31 13:32:25 vln000-dvl sh[175]: at System.ConsolePal.Write(SafeFileHandle fd, Byte[] buffer, Int32 offset, Int32 count, Boolean mayChangeCursorPosition)
Jul 31 13:32:25 vln000-dvl sh[175]: at System.ConsolePal.UnixConsoleStream.Write(Byte[] buffer, Int32 offset, Int32 count)
Jul 31 13:32:25 vln000-dvl sh[175]: at System.IO.StreamWriter.Flush(Boolean flushStream, Boolean flushEncoder)
Jul 31 13:32:25 vln000-dvl sh[175]: at System.IO.StreamWriter.WriteLine(String value)
Jul 31 13:32:25 vln000-dvl sh[175]: at System.IO.TextWriter.SyncTextWriter.WriteLine(String value)
Jul 31 13:32:25 vln000-dvl sh[175]: at System.Console.WriteLine(String value)
Jul 31 13:32:25 vln000-dvl sh[175]: at RI636.Launcher.Main(String[] args)
Jul 31 13:32:25 vln000-dvl sh[175]: /home/root/controller-start.sh: line 3: 178 Aborted ./controller/Controller < $STDOUT > $STDOUT
Jul 31 13:32:25 vln000-dvl systemd[1]: autostart.service: Main process exited, code=exited, status=134/n/a
Jul 31 13:32:25 vln000-dvl systemd[1]: autostart.service: Failed with result 'exit-code'.

I have little to no experience with embedded linux, could it be that that I am missing some flags in the service execution instructions...?

Thanks