UDP only works after deploy

Hi, I am using the UDP in node and i started to connect to it 5 days ago. I performed a test of 10 minutes. 3 Days ago i again used the UDP for 10 minutes. Today i wanted to send some msgs again, still the same settings and Node-Red was running the entire to, so nothing changed, but i did not receive anything. It started to work again when i deployed Node-Red without changing anything. As i want a robust environment i am wondering what went wrong, has it something to do with down, max up time, max sockets. The node info does not really help me.

TCP was still working and runs on the same port.