I ran into the same issue today.
This bug seem to appear, if you set editable
and selectable
at the same time. If only one or no is selected, it renders as expected. Both are selected by default.
If you need both options, just set them in code.
_textView.textContainer.exclusionPaths = exclusionPaths;
_textView.attributedText = attrString;
_textView.editable = YES;
_textView.selectable = YES;