I am a little confused.. i have started SIOC, then i started Oi4FS, The i do double click on the ngxu, SiOC is going Disconnected and started new, after some seconds it crashes.
The right thing to do for you is.
Start Oi4Fs, click an airplane image to start SIOC and then the correct airplane driver.
or just click the Oi4FS AutoStarter, that will start SIOC and then the the correct airplane driver based on which airplane is running in MSFS.
Oi4FS should stay open until it is closed by the user.