Sorting Products Manually - Isn't Working

I know how sorting products manually is supposed to work, but it isn’t working, and support can’t tell me why. They told me a week ago they were going to look into it.

I change to manual sorting in the collection, it says it’s saved, but the sorting doesn’t change when I click view or go to the live store to check.

Also the “best selling” sorting, does anyone know what data is used for this? Shopify support can’t tell me, they’re looking into this too. The best-selling list is automatically changing daily, sometimes more frequently than that, it seems that the data used for this must be just a few hours, or a day, seems very strange.

Thanks

Accidentally duplicated, please ignore.

Thanks for the reply. I’m not sure what you mean, though. When I select to order products manually, Shopify allows me to manually drag the products to sort them, and then I’m expecting the order I’ve manually sorted them, to show on the website in that order when “featured” is selected. Support told me this is how it should work, but it’s not working. Also, when I go into the collection and change the default order, for example to “price lowest first” that isn’t working either, it’s always manually sorting by featured regardless of what I change that to.