Why does panic: runtime error: invalid memory address or nil pointer dereference work, but separately?

Question

go

Good afternoon. I compose the code from other sources, it works separately (reconnect separately, receive messages separately), in the final version I get panic: runtime error: invalid memory address or nil pointer dereference . Tell me what I'm doing wrong. I tried to debug, but the stone flower does not work for me. Tell me where to dig. I am attaching the code, thanks in advance. https://gist.github.com/cascad-s/d6613665a714c6f6f...