The power data takes precedence over heart rate for the fitness points in the Strava app so you should strip the wrong power data completely from your activities. This can be done by https://www.fitfiletools.com/#/stripper#view
Or you could ignore the fitness points in ther app, because in the Strava web view you can display the fitness without influence from power data by selecting only the "Relative Effort" instead of "Power & Relative Effort":
