Sculk sensors react differently to wool occlusion depending on the global direction.

1- surround sculk with wool : 
W W W
W Sk W
W W W
2- walk over the wool: you will notice your steps will only be detected by the sculk when you walk over the directly north or south wool block, that also works with throwing a snowball.

it wont detect the steps if the character center (where the crosshair is when you look down) is out of the wool block border.

not sure if its intended, but im going to report anyways, keep up the good work and i hope it helps with it. have a nice day~

edit: change the title to have a better description. took a bit too long tho, my bad.