I placed a Jungle Half Drawer 2x2 in front of another Jungle Half Drawer 2x2 and the back one gliched out and became see-through.

Fixed in 1.16

This is similar to 944, 929, 924, 883, 815

Because #815 is the oldest, could you please close this ticket and add any useful information you have to that issue (mod version, game version, additional mods, etc)?