Occasionally when using "Show chunks" (f3+g), when mining the texture for the block breaking can appear away from the block itself, like at an angle or floating in the air. This also happens in 1.16.1 (I'm yet to test it on any other versions). 

Video of this: https://drive.google.com/file/d/1aYXGHvUGbj1TlrkuQTEnigCUK7kbE_yW/view?usp=sharing

(apologies for the music i didnt realise it was recording too)