Foxes can't see mobs that are in fenced areas or behind glass blocks

Example1:

What I expected: Fox sees the chickens inside the fence, and jumps over the fence to attack them (like in 19w07a)

What happened instead: Fox completely ignores the chickens, and doesn't even see them

 

Example2:

What I expected: Fox sees the tamed untamed Wolf inside the fence, and avoids it / runs away from it

What happened instead: Fox completely ignores the Wolf inside the fence and is unaffected by it.