I have the same issue. Every value above 32 has no effect. And with some testing the standard followrange turned out to be 32-34, while testing a zombie walking towards a villager. However a smaller value for "followRange" like 20 or 30 does work properly. (This being tested in a superflat and normal world.) Like @Black_tea_RGO mentioned, in 1.13.2, "genetic.followRange" worked fine.
Bas Boerboom
I have the same issue. Every value above 32 has no effect. And with some testing the standard followrange turned out to be 32-34, while testing a zombie walking towards a villager. However a smaller value for "followRange" like 20 or 30 does work properly. (This being tested in a superflat and normal world.) Like @Black_tea_RGO mentioned, in 1.13.2, "genetic.followRange" worked fine.