Magento 2.4.2 Homepage Redirect Loop After Changing “CMS No Route Page” Configuration

We are running Magento Open Source 2.4.2.

A site administrator changed the configuration under:

Stores → Configuration → General → Web → Default Pages → CMS No Route Page

After this change, the homepage started experiencing redirect issues and was intermittently inaccessible.

We attempted to restore the previous configuration by changing the “CMS No Route Page” setting and flushing Magento cache.

Current observations:

• Homepage: https://www.greatestgood.com.au/
• Product pages load correctly.
• Non-existent URLs display the expected 404 page.
• curl returns a 301 response for the homepage.
• We cannot determine which specific configuration value was originally changed.
• No custom code changes were deployed during this period.

Questions:

1. Can changing the “CMS No Route Page” setting create a redirect loop affecting the homepage?
2. Are there other Magento configurations (URL rewrites, base URLs, web server redirects, custom modules, SEO extensions, etc.) that should be reviewed alongside this setting?
3. What is the recommended approach for diagnosing homepage redirect loops in Magento 2.4.2?

Any guidance on where to investigate next would be appreciated.