Height doesn't increase from -1 to 0. The first image shows the height between the first and second blocks.
MC-238101
Height doesn't increase from -1 to 0.
Resolved
Cannot Reproduce
0
It appears you're so little below 0 that the decimal count actually can't show it (more than 5 decimals, eg -0.000001); try a /setblock at ~ ~ ~, it should appear at - 1, rather than 0; if you just move a little bit higher, it should get to 0/positive decimals.