I just bought a set of Meike macro extension tubes for my Alpha 6300. They work fine, with one exception: The AF confirms correct focus (green AF field) even when the display shows that the subject is strongly blurred. Without the macro tubes, the AF is fine. It seems (but I didn't check this thoroughly) that the AF with macro tubes works a bit more reliable with shorter focal length.
I didn't have this problem with my (now sold) Canon equipment.