I have a similar problem to you on a Chorus 11 speed cassette. Skipping on 17-19-21.
Would you mind posting a photo of these 3 cogs to show the level of wear.
In my case the wear does not stand out at all but skipping is really bad.
Will make a picture!
@gueron started
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I have a similar problem to you on a Chorus 11 speed cassette. Skipping on 17-19-21.
Would you mind posting a photo of these 3 cogs to show the level of wear.
In my case the wear does not stand out at all but skipping is really bad.