Just to clarify, it's not my personal server. It's my friends. I tested this contraption on MY server and it works perfectly fine, so I'm not sure what the issue is.
I'm trying to create some more complex redstone contraptions on a Minehut RP SMP and it's just not working, is there a specific plugin needed? The version is 1.16.4
I've included an example of what I'm trying to do (3x3 door)