Why does my PC running Plex not show up?

I have Plex on a PC and am trying to access it from a Fire Stick and Android phone. The server is working, connected to the network, has a static IP address, but can’t connect to the fire stick or phone. If I reboot the computer it works, but then after half-a-day later it doesn’t work anymore. I hate having to reboot my computer time and again.

It isn’t a firewall, and it isn’t an anti-virus software problem because I literally do nothing with my computer and it randomly stops connecting.

Any ideas?

can you share any details about your setup?