When a minecart is first placed down, the "minecart rolls" subtitle shows as it should, but when the minecart is moved (i.e. on a rail, or powered rail) it doesn't show. This issue occurs with all the minecarts (empty, tnt, chest, hopper, etc), and when the player is sitting in one.

(The screenshot shows subtitles for other sounds except "minecart rolls", while the player is in a moving minecart)