No network cable or cut / non-automatic IP

When I use Rasp3 + Volumio 2 last version configured with wired network with fixed IP and for some reason I remove the network cable, the system does not boot. With automatic IP and without the network cable connected, it works perfect.
Is it a software problem? Should not inform what happens? It took me several hours of tests to find the error.

I continue with this, I have problems and I can not find an explanation.
After running for a while, one or two hours, I stop watching My Music and I can not connect any other web radio. It’s like there was a disconnection of the network. But I can see and interact with the UI.
The network LEDs are blinking the green and the orange is on.
When I restart, the problem is corrected.
Regarding the previous post, I correct myself in this aspect: if the network cable is not connected, it does not boot. This is very strange, I think it’s all the same. Everything is very strange.
Please, I appreciate any help you can give me. If it’s my problem, I’ll learn something, if it’s a system bug I hope it will improve the fantastic thing of this software. I’m in love with him!