I've had this issue for a while. I found a similar post for 1.9.4 and tried the fix but it didnt work.
The problem is self explanatory. I can see the block in my hand and in an inventory(ItemBlock is working) but in world I cant.
I have other blocks that render perfectly fine, the only difference between them is that this one, has blockstates(Which work fine I think)
P.S, a thing I noticed, was that when I was looking at the blocks, where it looks like the registry name should be on the bottom right above the blockstate, it said null. Is that part of this same problem?
BlockFrame
RegisterBlocks
BlockRenderRegister