Block texture bug?

Hi
I have a problem using mapping inside a block.
The texture will only apply if the geometry is exploded to surfaces. Afterwards, it remaps itself randomly after closing and “saving” the block. https://global.discourse-cdn.com/mcneel/uploads/default/original/3X/9/a/9ae3ffcb3da10ef2b8fdd75a8c6069d0a7407886.mp4