Having strange problems with remote access, please help

I have not had a problem with remote access since I first started using Plex, been years. Anyway, for some reason yesterday all the sudden it started saying not available outside my network. The strange part… friends and family who have a Roku device can still access everything! Bbut any other device like an Android phone, FireTV Box, Xbox, etc cannot. It says server is online. I don’t understand why this is happening to everything but Roku’s nor how people can still access it when it says its not available outside my network. How can I fix this and why did it happen all the sudden?