First i'm sorry for my bad english... i'm French...
So, all my system is well working, but sometimes, the DNS adress is changing, and impossible to have the link ATV to Plex...and i have to reset it manualy.
my DNS server is set on Manual on ATV but, i don't know why it change, Plexify is working too
So the IP address you manually typed into your DNS settings on ATV magically changes without you doing anything?
Seems very strange to me, this shouldn't happen at all. After all that's what this setting is for, determining a static manual IP for DNS resolution on your ATV.