Scrolling down in grid view, the same set of observations appears again

Platform: Website.

Browser: Chrome 98.0.4758.102.

URLs: https://www.inaturalist.org/observations

Screenshots of what you are seeing: Issue not visible on a single screen.

Description of problem: Suppose you’re on the Explore page in grid view and you search for a species with a lot of observations. The UI loads a pile of observations, and when you scroll down to the end of that pile you get a little spinning arrow circle icon as it loads more observations. This repeats a few times until you’re at the bottom of the page and the set of next page / previous page and page number icons appears.

So, there’s a step where it displays the spinning arrows and loads the next batch of observations. Sometimes, though, it apparently loses track of its internal “next batch” counter. Instead of loading the next batch of observations, it loads the previous batch again. Maybe it skips a batch sometimes, too, though that error wouldn’t present visual evidence to me.

This is an intermittent issue. Some days, I never see it. Some days, I think the error rate in loading the next batch is in the 10-20% range.

https://forum.inaturalist.org/t/explore-page-shows-same-observations-twice/9243

Closing to focus on exising report (https://forum.inaturalist.org/t/observations-displayed-multiple-times-when-scrolling-in-grid-view/504).