So the "Corner Raised Bed" item has a weird collision on the inside of the corner to where you can't stand there because it has an invisible wall blocking it.

When placing it in build mode, you can see that it is very clearly sitting on a big square/rectangle and isn't affixed to a plane that is the same L shape as the planter box (like it should be).

The invisible blockage prevents player from being able to plant seeds in the front/shorter shelf of the box.