Moving up/down in 1.16 Pre-release 1 during rain/snow causes the rain/snow texture to jitter, or perhaps change Y cordinate.

Would probably be hard to see during survival gameplay, as rain moves quite fast. I was only able to notice when I jumped from a cliff while looking up, expecting to follow the rain downwards as I used to do in previous versions, but jarringly noticed that the rain was changing and flickering constantly.