No you are not doing anything wrong, Audacity has decided to always import 24-bit files at 32-bit resolution instead of 24-bit - even if default sample format (Quality Preferences) is 16-bit or 24-bit. See change dither to none? in quality settings? - #11 by Gale_Andrews . This contrasts to seemingly more expected behaviour for FLAC change dither to none? in quality settings? - #14 by Gale_Andrews .
I know of no necessary reason to always import 24-bit files as 32-bit, so you can request it be changed and we’ll count your vote towards it…
Gale
I’ll see your vote is counted - the votes are kept at Missing features - Audacity Support but you need to request a Wiki account to edit the Wiki.
If you want to vote for other features on that Feature Requests list, please write to our feedback address .
Gale