All of the urls on the site default to 404 pages. It was just noticed about 4hrs ago. The menu items, the buttons, the links, everything shows a 404 page.
The site is developed with the JA playschool quickstart on Joomla 4.
I tried to disable URL Rewriting option under SEO settings in Global configuration of your site and it works normally:
It means that there is specific rule on your server side that caused this issue, you can contact your hosting provider for help to check on this.