Two things.
With the rod with the "problem" neck expander secured into the die body in it's usual position, flip the die around until you are looking up into the die internals. Is the rod centred nicely in the die cavity ? It's not unusual at all, especially with Hornady dies, for the rod to be off-centre. Cure this by loosening the lock nut, turning the rod either up or down slightly until it's nicely centred, then reset with the lock nut. This might prevent or reduce brass scraping.
If that doesn't help you could swap the standad neck expander for an "elliptical" neck expander which Hornady sells as an after market part. Personally I use these in all my Hornady dies as they pass through the neck much more smoothly. I believe this smoother passage also helps keep cartridge run-out in check but sgain, ensure the rod is nicely centred in the die cavity.
https://www.deltamike.co.nz/product/...expander-ball/
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