An error in the form: “Error: Data receivers from another website are linked to the form. Go to the form content, select data receivers, and republish the page.” Why?

Only one assigned domain (and all of its subdomains) can receive applications.

Go to Site settings → Forms → scroll down → click General forms settings → set the Domain for data capture services → Save → re-publish all the pages.

Before reviewing the forms, refresh (reload) the page 2-3 times in a row.