Sometimes when trying to jump 2 blocks high(for example while climbing mountain) using water bucket, water gets "picked up" in bucket after jump but source is still in the same place. It's especially annoying because "water bucket" is actually without water, so then I can't get down the mountain without killing myself. This bug occurred in many previous versions not only 1.16. I think this bug is server-sided. That's why bucket empties after relogging.