Setting up Odoo reCaptcha can cause issues. A common mistake is using the wrong site or secret key. Always copy the correct keys from Google reCaptcha settings. Another issue is reCaptcha not showing up. This can happen if API scripts are missing. Check the browser console for errors. If verification fails, ensure the domain matches the registered one. Using the wrong reCaptcha version can also cause problems. Choose the right version (v2 or v3). After making changes, clear the cache and test again. These steps will help you set up reCaptcha smoothly.