When you start the boat the computers will run their diagnostics, you will see all the gauges, including the wake plate gauge, move up and down and then settle. It'll take a few seconds. It'll always settle with wake plate at 100% until you take off and reach cruise speed. If your surf tab toggle is flipped to one side or the other it'll mess up the diagnostic run and the wakeplate will stay at 100% and will not move.
So, when u start the boat, make sure your surf tab toggle Is in the middle. Same for when you shut down and restart the boat at any time during your day.

THis is something that drove me crazy, even my dealership could not give me the answer, I actually called skiers choice and they were the ones to give me the explanation.