When you crouch your hit box should get shorter.
If you are inside a block the hit box doesn't get short when you crouch. https://gyazo.com/3e6cc7d6f27dfddabbe7b4887fa35933 This can commonly happen with trapdoor/gates and can cause player to get trapped in some situations without knowing why. https://gyazo.com/989fc5a9b64388897b1478b079194c86 This behavior is different than 1.12.
in 20w18a