Windows 10. Android Samsung galaxy s6
Log files from the server? (https://support.plex.tv/hc/en-us/articles/200250417-Plex-Media-Server-Log-Files for the file location) Are you using uPnP on your router or Port Forwarding? (Did you manually specify a port in the sever’s settings?) What make and model of router? (Would help to find the page numbers in the manual so you know where to look for the info.) How does your ISP provide you with internet? Do they also provide you with a router? (Do you have your own router afterwards?)
Have you worked your way through this support document? https://support.plex.tv/hc/en-us/articles/200931138-Troubleshooting-Remote-Access
Ignore the parts about uPnP and get right down to double NAT and Port Forwarding. This is where the really important stuff is at anyway on that document. uPnP is way to problematic for a 24/7 server to expect it to run without some pretty high end routers/switches, and if you had that kind of hardware already, you likely would have forwarded ports to start with.
In order to help you, you need to help yourself, first. by making sure those willing to help have as much information as possible to help you out. You haven’t done that, so all anyone can do is ask for more info.
