Since it is committed, it has to have gone through, but something either in the change or the display is clearly wrong.
https://www.inaturalist.org/taxon_changes/47749
Best guess is that a hard drop was applied to the other taxa ?
Yep, that’s a weird one @cmcheatle. Exploring the information on the Tryonia taxon page, it looks like the only candidate for the missing input taxon is Durangonella, which is also mentioned in the source reference for the swap.
https://www.inaturalist.org/taxa/search?utf8=✓&q=Durangonella&is_active=any turns up nothing except Tryonias.
I suppose the original creator of Durangonella might have deleted the taxon after the swap???
Looks like someone deleted the taxon change itself too. Marking this as resolved, I guess!