I think you have to port forward in order to use it locally like that because of your router, at least thats what blocked me and ive admittedly never messed with my router before. I got around this issue by using rustdesk to remotely connect to my computer which admittedly is a bit inconvenient to use that way, but it works! (Minus the weird android keyboard bug where the keyboard gets stuck typing one character instead of what you're typing, and autocorrect doesn't work. Though this may just be an issue with Samsung's virtual keyboard implementation and i got around it by just going in and out of Rustdesk on android, didnt even need to close it.) 

Also note that you may have the issue of the power button on your monitor turning off your monitor instead of just cutting the visual feed, I had that issue with my main monitor, though my second monitor doesn't have that issue.