Iron golems walking throw iron walls that are 2 blocks high

I was building a new design of an iron farm, When I saw the bug, I thought it was my own mistake. After that I saw iron golems getting pushed throw the walls. I was able to push the iron golems my self through the walls. I didn’t see any iron golems spawn is the walls, but I'm sure it could happen. the hight was -17 blocks. (on super flat)

In my opinion this is an urgent bug to be fixed in Minecraft Java.