Error at Login - "The action you requested is not allowed

The problem is back so clearing the cache was not the issue, it appears.

Am not seeing this in the console;

Access to XMLHttpRequest at 'https://www.example.com/?debugbar_time=1675914178' from origin 'https://example.com' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.