Recently changed domain name. Home page widgets are now not in the customize menu yet still being on the page

Perhaps something in the database is still referencing the old domain name?

Use a plug like “Better Search and Replace” to search (only) the database for your old domain name. (If you are brave, you can use SQL commands to do that. But that plugin – or similar – are much easier.)

(You may need to do a search/replace anyhow, as media file links will have the old domain name.)

Backups are important before any major changes.