Happening here as well. It's dumb because they're using an infinite scrollbar rather than page selectors for pagination which means you can't say 'reload from page 2' but instead just suddenly stop getting results when scrolling. If you refresh the page, you don't get any search results. Their rate limiting is way too aggressive. They're probably trying to protect against bots, but it's obvious the setting is affecting normal users even when logged in and has been for months so I'm guessing they feel the bot prevention is worth user discontent.
For others who find this, reduce the number of filters that you're using and it'll stop. I'm guessing that their way of using filters issues multiple requests to the API or something and that is causing too many calls and thus the 429. I only used two filters (windows and free) on top-sellers with one tag and couldn't view the page for more than 2 minutes without a 429. I only removed "windows" and left everything else the same, and it stopped throwing errors.