When a boat lands in the 5 pixels of the 2nd last flowing water, the boat or raft will fall through the solid block below. (the same number of pixels of a stage 0 coco bean)

On older versions it is the 3rd last flowing water

Doesn't appear to be chunk aligns or rotation but the y valve might have a factor

Video link showing bug in 1.14, 1.19.2, and 22w45a: https://youtu.be/HIBZ0xSLX0Y (video size was too big to attach)