Using a CALayer to highlight text in a UITextView which spans multiple lines

This is a continuation of Getting CGRect for text in a UITextView for the purpose of highlighting with a CALayer. I'm having trouble with getting the correct rectangle for the ranges in each line fragment.

NSString* searchString = @"Returns the range of characters that generated";
NSRange match = [[[self textView]text]rangeOfString:searchString];
NSRange matchingGlyphRange = [manager glyphRangeForCharacterRange:match actualCharacterRange:NULL];



[manager enumerateLineFragmentsForGlyphRange:matchingGlyphRange usingBlock:
 ^(CGRect lineRect, CGRect usedRect, NSTextContainer *textContainer, NSRange lineRange, BOOL *stop) {

     NSRange currentRange = NSIntersectionRange(lineRange, matchingGlyphRange);

     [manager enumerateEnclosingRectsForGlyphRange:currentRange withinSelectedGlyphRange:NSMakeRange(NSNotFound, 0) inTextContainer:textContainer usingBlock:
      ^(CGRect rect, BOOL* stop) {
         if (usedRect.origin.y == rect.origin.y && NSLocationInRange(currentRange.location, lineRange)) {

             CGRect theRect = [manager boundingRectForGlyphRange:currentRange inTextContainer:textContainer];

             CALayer* roundRect = [CALayer layer];
             [roundRect setFrame:theRect];
             [roundRect setBounds:theRect];

             [roundRect setCornerRadius:5.0f];
             [roundRect setBackgroundColor:[[UIColor blueColor]CGColor]];
             [roundRect setOpacity:0.2f];
             [roundRect setBorderColor:[[UIColor blackColor]CGColor]];
             [roundRect setBorderWidth:3.0f];
             [roundRect setShadowColor:[[UIColor blackColor]CGColor]];
             [roundRect setShadowOffset:CGSizeMake(20.0f, 20.0f)];
             [roundRect setShadowOpacity:1.0f];
             [roundRect setShadowRadius:10.0f];

             [[[self textView]layer]addSublayer:roundRect];
             *stop = YES;
         }
     }];
}];

This my current attempt. I'm basically using enumerateLineFragmentsForGlyphRange:usingBlock: to cycle through each line. Then i'm using enumerateEnclosingRectsForGlyphRange:withinSelectedGlyphRange:usingBlock: to make sure the range of the text on the current line matches up with the line's range and has the same Y coordinate. Sometimes this works, and sometimes it doesn't.

It seems that if the search text is near a return it draws the highlight way off. (the y coordinate).

In this screenshot "Returns the range of characters that generated" is supposed to be highlighted.

It seems if the text is not near a return or whitespace this works correctly:

Am I missing something?

UPDATE:

I've narrowed the problem down a bit, I believe enumerateLineFragmentsForGlyphRange: usingBlock: is skipping over lines which have returns.