1.14.2 Slime chunk spwaning

Slime aren't spawning in slime chunks in 1.14.2.

The new spawning mechanic where it takes in the fact of the highest block in the chunk (know of it but don't exactly know how it works) appears to prevent slime from spawning in a slime chunk when the spawning platform. Have tested it removing every block above the spawning platform and got spawns but the rates were very slow.