@dayglojago 

All your devices, including the Plex server, are connected to the Deco?
 

Were you previously able to access your Plex server from a web browser?  If yes, is it still possible?

  @yves_b Yes, everything is connected to the deco, it's the only router on my network.

It is no longer possible to connect to the web interface where it was before from other machines on the local network. Sometimes it's possible to connect, but only intermittently an never reliably.

  @dayglojago 

So the web interface works sometimes, but not for long?

Or does it work for some activity, but not for others?

Can you do a speedtest from the Plex server?

  @yves_b the web interface will *sometimes* load, but most often will get stuck on a half-loaded screen. It's not really functional either way.

i did do a speed test on the Plex server. I got full throttle on my connection, which is 500/50 down/up

  @dayglojago 

Do you consistently observe that "small" web pages work well, but large do not?

  @yves_b no that's not something I've noticed

  @dayglojago 

OK, too bad the issue is not consistently reproducible.

Anyway, I suggest having a look at the MTU setting on your Plex server.

  @yves_b The plex server can't be reliably connected to, much less streamed from, I'm not sure the MTU setting is going to help, but I'll take a look!

  @dayglojago If the server sends frames larger than what is supported by the Deco, that could be the cause of some issues.

  @yves_b Fair enough. Now the server isn't being detected at all, despite running. Sigh. Where do I change the MTU settings? I see nothing similar except the buffer size.