I summoned arrows with repeating command block like this:

summon arrow ~ ~ ~1 {Motion:0.0, 0.0, 1.0], NoGravity:1b}

(the speed of an arrow and other nbt tags which are not written here don't care to this bug),

and put any block at the trajectory of the arrow, and then I destroyed the block. Then, some arrows seem to move a lot slower than other arrows, which are just summoned. What is happening to arrows? I could check this bug on 1.14.4, 1.15.2, and 20w17a.