I was also able to connect a my Green wallet to a random Electrum server and it synced without any problem. thus, I believe you should be able to connect it to your own server too.
I think the issue is with green is that like Coinomi it needs a valid SSL because it does connect to the 1 node I have with one.
BUT, for internal testing I just hit the 192.168.1.x private IP.
Apprently, that's no longer possible. I tried to connect to my own server, it just get stuck at "SPV synchronization..." and whenever I make a transaction it says "SPV unverified".
I reached out to @BlockstreamHelp in Twitter, and this was their response:
@DaveF Have you tried BRD wallet? It says "Connected" even when I put an invalid IP address. The payments are going through just fine so I can't tell for sure if it's not working and I'm being connected directly to BRD servers, or it's just because I didn't configure my node properly.
Green:
Hmm, just tried again it did connect to the node with SSL but not the one with just an IP.
With that being said I also just noticed it's a much older build of green. For some reason it has not updated in a while, I never noticed, that might be it.
BRD: I want to rebuild the VM that I have the Electrum servers on 1st. Just with everything going on with Corona / the shutdowns now I have about a dozen projects / testing things that are all in various states of progress.
I kind of work on them when I figure I have "X" time and this next step should take "X" time so it's good. If it turns out to take longer or I have less time it can all get pushed back or just stalled.
Stay safe.
-Dave