Afraid it’s been hit by two diseases SQWIB.
The leaf has got Scab and the shoot tip Mildew.
Both are diseases that you protect against by spraying.
This late in the season just cut off any shoot tips that look like that one and burn.
Next year spray a protective scab / mildew spray from early in the season. The sprays protect against the spores of the diseases...they won’t kill established infections.