Our trip at the beginning of February was fine as far as using the app to update FP+. The only, maybe obvious, thing was DO NOT change FP selections by deleting them and trying to then make new FP selections from the app. Use the change experience/time selection! The first day we had some problems and had to go to the FP+ location to sort it out and by the time it was sorted out FP for the ride I really wanted were gone.