When I was playing in survival, i got aqua affinity from a villager, and then accidentally put it on my BOOTS. I am pretty sure you can't do this, since aqua affinity is a helmet enchant. Then I went to go test it in the water to see if I can mine faster, AND I DID. I also went on to 1.16.5 and this did not occur. (1rt picture is 1.17) (2nd picture is 1.16.5)