Slime don't spawn in slime chunks - 1.14.3

same issue here. Have 3 slime chunks and they don't spawn. Also they are not spawning in swamps.

Edit: in 1.14.2 they were spawning.

Also experiencing this issue

Small edit: They still spawn in swamps correctly from what I can tell

I have the same problem, they don't spawn anywhere only with /summon slime

Indeed they have stopped spawning in slime chunks, however, they do still spawn at swamps at a lower rate than before 1.14.

Duplicates MC-153326.

I have the same problem, the world was created in 1.12. I tried recreating it in version 1.14.3 but slimes still do not spawn on the same chunk. I used Chunkbase's Slime chunk finder and Amidst to find these slime chunks. 

FIXED: If you are using Optifine, disable Lazy Chunk Loading in Video Settings >> Performance

@William Smith Thanks! that helped a lot

william smith what that do