Disappearing contraptions in Create: Aeronautics

I am testing out my modded server and I've been having this issue with create aeronautics contraptions occasionally disappearing and doing this weird thing in the video above where going up close to it makes it disappear but backing away makes it show up again. If any knows any solutions or causes, do let me know because I've been really wanting to start up this server for my friends to mess around with aeronautics.