I've thought this through and discussed it with a couple of guys who are pretty good wave sailors.
The concensus seems to be that you are trying to make your turn with too little speed.
Would it not work to sail out a bit further and "overtake" your wave with more speed?
Then you can sail right onto the face with power, and make your bottom turn on the face where your board can accelerate more easily, and the wive will be formed up better so you don't have to "wait at the bus stop" for the face to catch up.
If we could see you in action, it might be very easy to tell precisely what's happening.
Hope this helps,