Please head over to WordPress Dashboard > Rank Math > Titles & Meta > Authors
Disable the author archives:
It should work after that.
If that doesn’t work, we might need to take a closer look at the settings. Please include your WP logins in the designated Sensitive Data section.
It is completely secure and only our support staff has access to that section. If you want, you can use the below plugin to generate a temporary login URL to your website and share that with us instead:
It looks like one of your installed plugins is causing this issue. Unfortunately I have just installed the Healthcheck and troubleshooting plugin on your site but this has caused a redirect error.
Please login to your site via FTP and rename the Healthcheck plugin folder in wp-content/plugins directory.