If you try to hit a silverfish or endermite from 2 blocks directly above it, you will hit the block below it instead. This only occurs in survival mode.
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migrated
Erik Broes
Working as intended. Your interaction range is lower than the block-interaction range. When aiming at something that you cannot interact with however we now make sure you cannot reach the block behind it.
Erik Broes
Can confirm, although using F3+B to reveal a mob's hitbox, you still can't hit them. (Silverfish and Endermite)