Platform: Website
Browser: Chrome
URL: https://www.inaturalist.org/taxa/4203-Podicipedidae
Screenshots of what you are seeing:
Description of problem:
The numerator of “Total Species Observed” includes the extinct Atitlán Grebe, while the denominator excludes it. This is the same manifestation (though perhaps different underlying issue) as this now-closed bug: Total Species Observed on taxon page should exclude inactive taxa