When walking and mining, you may a lot of times see a bugged-out block hitbox. It lasts for less than a second, but happens many times when mining multiple blocks. I have managed to screenshot it, despite how quickly it can disappear:
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Hi there!
This looks like a duplicate of MC-194173. If you’re not doing so already, make sure to do a quick search for your bug before posting it. If you find it, vote for it, comment on it, and watch it. This is the best way for it to be prioritized by Mojang. Making a duplicate post means more work for the volunteers who help out to moderate and clean things up for the developers to look at and fix what needs to be fixed.

Indeed, this is duplicate.