A note on practice which may be helpful. A common practice problem can come from not concentrating on 'tricky bits'.

A 'tricky bit' can be just one or two notes in a bar which require finger movements which are unfamiliar. You have to figure out what the problem actually is, and work out a solution for that problem. You then practice just this bit until you can do it.

If a section registers as tricky, this implies that the rest of the piece is doable. Therefor the main concentration of practice on that piece should be on that tricky bit until it is no longer tricky. This might sound obvious but if I had a student who got stuck I would look for something like this and I would look at how the student approached it.

It's not just getting the tricky bit learned. You then have to practice the resolved tricky bit with the preceding bar or two or four. When you can do this consistently you have to practice this group of bars within the section. When playing the whole piece you have to be able to flag up the approaching ex tricky bit in order to be ready for it or it will still fail.

Identify and solve the problem, learn the solution and then integrate it into the whole piece.

I hope this helps.