»need help with multiplayer worlds

So i have a vanilla survival server with some plugins like mcmmo and tp/home and there is a certain place on the server(my house with only one tiny piston door(1x2)) that causes a sudden drop in tps(ticks per second) and i'm completwly baffled on what could be causing it. Please admins or anyone with some insight, help me out

 

First things I would check for are large light updates happening because of the door, e.g. is some large area below the door becoming exposed to sunlight when the door opens?

And check your redstone. There could be a feedback loop causing lag until it's resolved.

Build the same door on the ground out in the open. If you don't get the same behavior, the problem is with the door as it's installed. If you do, the problem is probably in the server config.