Images:
Build Mode : Able to remove top wedge.
Build Mode : Unable to remove wedge under top wedge.
This bug also happens when removing blocks while you are "no-clipped" internally, or any block behind another while you are "no-clipped". So without a direct line-of-sight or path to the block they can not be removed through build mode without first removing the preceding block. This creates game breaking workflow issues when trying to configure / alter blocks in confined spaces or inside of an already completed ship.
Happens with all shapes and types of block. Untested with sprites (I.e. Capsules / Grass).