I tried to re-create this error, but could not.
When you use ancestry.com to search for Charles
Reynolds, indeed, you do not get the
Columbia manifest, but the manifest for Principe di
Piemonte.
However both manifests are on Roll T715-1215. They arrived a day apart and the Principe di
Piemonte is in Volume 2675 and the
Columbia in Volume 2676.
There is no way that a manifest would be found in Series T621, as that series contains soundexed indices T621-589 contains R543 through R552.