Villagers get stuck trying to push their way through any blocks that are placed diagonally. In one house i built there was a diagonal wall, and instead of leaving through the door, the villager tried walking through the diagonal wall. the same thing happens with stone walls (and other types of wall blocks) that are placed diagonally. I saw another bug report about pathfinding being "fundamentally broken" and I think I agree
Related issues
Comments

Duplicate of MC-142817
it was fixed in 1.14.1 Pre-Release 1