Hello,
Thank you for contacting Rank Math and bringing your concern to our attention. We are sorry for any inconvenience this issue may have caused you.
Please head over to your WordPress admin area > Rank Math > Titles & Meta > Authors, and enable the Author Archives:

Once done, clear your website’s cache and test the page again with the Rich Results testing tool and see if the issue gets fixed.
In case the issue persists or was already enabled, please delete the Schema from that page and update the page. Then, add the Schema again and see if that helps.
Let us know how this goes.
Thank you.
Hello,
Since we did not hear back from you for 15 days, we are assuming that you found the solution. We are closing this support ticket.
If you still need assistance or any other help, please feel free to open a new support ticket, and we will be more than happy to assist.
Thank you.