https://www.tp-link.com/uk/home-netw...specifications
One or more of the " advanced functions" listed here are probably to blame. Try disabling as much as you can, then re enable things one at a time once it works again
I wonder e.g. what web filtering does,. By default
I read all the fancy hype but I don't see how it does basic lan management. If your content server does not get to live on a fixed lan address then how is it going to work.
Did it come with an actual technical manual or does it claim to be so smart that thou don't need to know how , what it's doing ?