From the iNat homepage, I clicked on Your Obervatoins, and then clicked the Filters > Download button. That sent me to the Export Page at the following URL: https://www.inaturalist.org/observations/export?verifiable=any&page=1&spam=&place_id=any&user_id=pisum&project_id=
Looking at the Place filter input box in section 1, the page loads with the search indicator spinning (as shown in the picture below, circled in red), and looking at the Network activity the browser, the page seems to be issuing a request to https://www.inaturalist.org/places/search?q=any. The problem is that I didn’t actually look for any places, and the request seems to return places that have “any” in the place name (ex. “Anya’s Abode”).
If I type a place name into the input box (after page load), it will filter fine. Or if I input an actual place_id value in the URL (not “any”), the place input box will be pre-populated with the place specified in the URL. Or if I remove place_id from the URL, the page will load without trying to filter for “any” places. So it seems like the the page still works fine in general. There’s just the small quirk with place_id=any.