Lots in Willow Creek Disappear

Hi there @BriteRedScream are other worlds loading normally for you and is it all lots affected or specific ones? Were the affected lots from the Base Game, created by you or from the Gallery?

You could try clearing your locally saved data as a first step. If you haven't done that before go to Sims 4>Manage Game and Add-ons by clicking the button with 3 lines on the Sims 4 on your console home screen. On the next screen go to your Saved Data, click that and you'll see 2 sets of data. Pick the smallest set of data next to your gamertag and select delete from console only. Then load up your game and it will carry out a data synch as it's loading.

If that doesn't make a difference I'd then try reinstalling your game.

Are you having any other loading issues? Like long loading screens or excessive buffering in Manage Households/Other Households? If so it may help you to clear some space by clearing out items from your library and deleting some townies from Other Households. I'm also on Xbox Series X and I'm constantly keeping a check on my game storage. I delete a few Townies most days and I never keep many items in my library.