I built a cabin in a taiga biome in 19w07a. On the outer walls, I placed a torch on the wall, followed by an intem frame, and displaying a stone slab inside the item frame. (i've added a picture named "torch example" for you guys to see what I mean). After updating to 19w08a, all of those torches popped off the wall, including the item frames and the slabs which were being displayed inside those item frames. When I tried to place the item frame on those exact blocks, I would see the placing animation, lose one item frame from my inventory, but no item frame would be seen anywhere on that block. Then I proceeded to place the item frame on the floor, and I would get the one item frame back, which I had previously placed on the wall. I've also included a video showing this glitch for a better understanding.

https://youtu.be/EtTEKtE_kVk - video explaining the bug in more detail. sorry for my bad mic quality