Particles should spread not further than 7 blocks from world bottom (or maybe frog fog start setting)
There is 1.2.5, as you can see, particles have height limit

On 1.20.4:

UPD:
Since the appearance of fog parity to the old versions was achieved by changing the fog start from -64 to -48, the particles should have a height limit: max_height < (fog_start - 9)