One common thing I see a lot with batsmen is a "broken" wrist.

Not damage to then bone, but instead the wrist has wrapped itself around the bat when you drive.

It might be because you are holding the bat wrong to start with. That's often true with beginners and very young players. More often it comes from a good intention; you are trying to keep the bat straight. Sadly, doing it that way means you lose a lot of control and power.

So, instead, learn to keep your wrist strong during your swing. It's why your coach says "keep your elbow up", because when you do that, you are also keeping your wrist in a good place.

Sometimes it helps to think of your shoulder (or even your head) as the part that controls the swing of your bat. That way, your hand and wrist become really the interface between you and the bat. It's just a connector, it doesn't need to move.

Whatever the reason, and whatever the cue that works, video yourself to see how you look and work towards keeping your wrist strong.