Perhaps you need to have the Newtonian physics on (or off)

Gravity wall explanation
Gravity wall is a special type of wall that any element can go though. When Newtonian Gravity is off, gravity wall does nothing, and is little more than a yellow striped decoration. When newtonian gravity is on and you have a black and/or white hole out somewhere however, the elements that are in the wall are not affected by the gravity. So drop some water in the wall while a black hole is to the left of it, and it will fall straight down instead of falling towards it.

@person (View Post)
You need to have an enclosed space to make it work.
If the space is enclosed, gravity from BHOL/WHOL can not get in or out.

How do you turn on Newtonian Gravity

Next to the rest page button theres a button that looks like a small checkmark, click that for options and you can toggle newtonian physics there