When you filter by place on a taxon page, the number in the badge for similar species is filtered by that place, e.g. the 869 on S. niger becomes 21 when filtered to Canada.
But when you click on the badge to link out to those observations, it always uses place_id=any, so in this case, clicking on the 21 takes you to https://www.inaturalist.org/observations?ident_taxon_id_exclusive=46020,46017&place_id=any&verifiable=any, which returns 869 observations:
I expected that it would take me to https://www.inaturalist.org/observations?ident_taxon_id_exclusive=46020,46017&place_id=6712&verifiable=any, which would show me only the 21 observations in Canada:
