Simulink Modell - Run on Boot

Hello Everyone, i got a question i cant solve by my own and i wanted to know if some one faced the same Problem i did.

Context:

I need to deploy a Simulink Modell on a Raspberry Pi 2B+ which first does not work but now it works.

Because i want the modell to run on every reboot of the System, i clicked the check box "run on boot".

This actually does the job, i can see the process running and also see the results on my RC-Car.

The Raspberry is connected via. CAN to a Arduino and the communication is working...

Problem:

How ever this only works if i deploy, and start the Modell directly out of Simulink.

Then the CAN Connection is working perfectly doing all the jobs it should.

But when i reboot the system, the modell starts as it should, but the CAN Communication terminates after 20 seconds.

The CAN Communication is not the problem i guess because its not deployed over Simulink i use a different Bibliothek and alsi the Process is running.

What i dont understand is, why is it perfectly working after i "press deploy and start" but will fail after an reboot when "run on reboot" is activatet.

Did someone faced a simular problem?