[MP4] Valley editor texture bug

[Iceman]

I just found this bug while building a track (yes its lagging cuz of my bad pc)
https://youtu.be/uaRA3fm5gOQ

Also if you place these blocks in the other way (1-4-6 first then 1-4-3) the 1-4-6 block just disappears

After undo reundo i got this