Ive had Plex for years and have had no real issues until now.
Last week or so, i noticed the picture quality was lower when streaming content, went into the settings and noticed remote access wasnt available. So my fix in the past was to to turn it off and on again and it would work.
this time after i shut it off, I got a"Unable to connect to ‘server name’ securely" error. this just loops trying to connect.
not sure about the stream quality but for the remote access what I did was: under remote access, select the “manually specify public port” and then I manually forwarded port 32400 on my router to my plex servers IP. give that a try
Edit: for the quality problem, under Network in settings untick the “Enable Relay” box and see if that helps