Not exactly a piece of the site I use frequently, so I have no idea if this is new or has always been there etc, but it seems when I look at this page, the language used to label observation taxa is inconsistent :
https://www.inaturalist.org/subscriptions?page=3&type=observation
So for instance in there is a mix of English and French names, further down beyond the scroll there was Spanish etc.
My first thought was that it might be just picking up the default overall name for the species as defined on the taxon page, but that is not the case. For example the 4th entry ‘Cardinal à poitrine rose’ - that’s the french name for Pheucticus ludovicianus. It is not the default overall name for the species (oddly that is a Spanish name), nor is it set as the default for Canada, which is my default place names setting.