Ater-tax 401k contribution conversion - does prorata rule apply?

Are there consequences if I have a balance in my pre-tax 401k account when I rollover my after-tax contributions to Roth?

I’m getting conflicting information that suggests this would be treated the same as Roth IRA conversions. For example, I’d have to include some of the pre-tax contributions in the conversion based on the pro-rata balances at the time of the conversion. This would mean some of the conversion would be recognized as taxable income.

This is exactly what I was thinking but he didn’t touch on it

Thank you so much. Just replied to your question on the Directed IRA Podcast on 11/3. Should be published in the next 2-3 days. Please get over to our ‘sister podcast’ - The Directed IRA Podcast. THANKS AGAIN!! Mark and Mat