Hello,
If you are using a caching plugin like Rocket cache on your live site, it’s possible that the cache is causing conflicts with the updated theme files. Clearing the cache can help resolve this issue. Additionally, make sure to disable any other caching plugins temporarily for testing purposes
Disable all plugins on your live site and check if the 404 errors still persist. If the errors disappear, reactivate each plugin one by one, checking the website after each activation.
If you have any questions please feel free to contact us.
Best Regards.