Hi,

To fix your localization in Odoo 17 after creating a fiscal position incorrectly changed taxes and accounts, start by identifying the problematic fiscal position in Accounting > Configuration > Fiscal Positions. Review the "Account Mapping" and "Tax Mapping" tabs within that fiscal position, correcting or removing any incorrect mappings that are causing the unwanted changes. If the fiscal position is unnecessary, delete it after ensuring it's not assigned to any customers or vendors.

To restore default taxes and accounts, manually revert them to their correct settings or, as a last resort (with caution), try reinstalling your localization module after backing up your database. Clear the Odoo cache and thoroughly test your accounting setup by creating test invoices and bills. Remember to activate developer mode for advanced settings and consider consulting an Odoo expert if needed.

Hope it helps