Remote Access: Hit and Miss



I have enabled Remote Access while signed in to my Plex Premium account. After about an hour, with no apparent changes, it shows red and says Remote Access not available. I have to sign out and sign back in for it to re-engage, but it only lasts for a short period of time. I have checked my modem settings and have tried manually port forwarding to no avail. I think I need to go back to square 1, can anyone help me with this?