Why can't I find an extract?

Probably because it's a payroll or seeded localization extract which is Legislative Data Group (LDG) enabled and you're looking in the Data Exchange work area. Search for your extract by LDG using the Show Filters option in the Extracts Definitions UI.

You need to use the Submit a Flow task in the Payroll or Data Exchange work area to submit these types of extracts.

Inactive extracts aren't available in the default search either. You can search for inactive extracts by using the show filters option.