You might know that sandstone's texture connects to other sandstone blocks in OptiFine. I made that but in vanilla Minecraft. However, because of the method i used, the top disappears with ANY solid block on top, and i cannot do anything to fix it.

In case someone asks me to do an connected glass resource pack: I cannot without making it look good. There is an pack called Seamless glass, which does that, but also has the same problem i had when trying to make my own.