It may worth mentioning that both those tutorials are made for local use (server and Electrum on same computer).
So for accessing it from mobile that may need a little more configuration.
As it seems as a private/home solution, testing connection in the same network should give the answer if all is configured properly.
For access from outside, probably router configuration should be checked, if static ip is used (or dynamic dns solution). Or server should be configured to use TOR. Anyway - it means computer must be switched on all the time. I think sooner or later OP will come to the conclusion that a separate machine for that purpose is a better solution (PI or NUC etc).