What could be the causes (and solutions) of a database missing "Fiscal Localization" selection in Settings>Invoicing?

The localization is installed but not working properly. Trying to unistall and reinstall will leave the module broken, and only upgrading does nothing.

Tryied reproducing the error on a new database with the same modules installed and the error can't be reproduced.

Might be relevant to point out (or might be usless): 

The database was not originally on Odoo14 and was migrated at some point to Odoo15. The database also used odoomates accounting for CE at some point but is no longer installed.