Villagers tracking the way out of stair blocks

Villagers can see through stair blocks making them able to detect hostile mobs and start running due to panic but they seem to consider stair blocks as paths and start escaping from it

What I expected to happen was...:
I wanted villagers to stay inside the pyramid made out of stair blocks and move within its range like they pathfind through normal blocks

What actually happened was...:
Villagers end up path finding through stairs and start moving through stairs , ignoring its presence and ending up dying

Steps to Reproduce:
1. Collect a bunch of villagers in an area away from golem

2. Make a pyramid shape with stairs only and don't use any other block
3. Start creating a little of panic by triggering raid or releasing a hostile mob