The fuses are a known weakness, partly because they catch any water leaking in through the screen.
Once you have had a fuse get hot, it makes the problem worse because the heat softens the retaining plastic and also reduces the springiness of the fuse clips.
Try changing to another spare if you can, or as a last resort wire in a new fuse separately. They can get hot simply because the contacts are getting corroded, and that sets up the whole cycle.