Hello,
Thank you for contacting Rank Math support, and sorry for any inconvenience that might have been caused due to that.
I checked the URL you shared in the Rich Result Test and it seems to be returning without any warnings or errors as you can see in my screenshot here:

Can you please try clearing your website cache and check again here?
Looking forward to helping you.
You right in Rich search test it is showing everything is fine. Just because author URL is optional. Rank math is not generating that URL with schema. I need to add that URL in schema. I know it’s option, but I need it to be there. Have a look at screenshot I attach. It is showing author url is missing.
https://ibb.co/xqMWLCq
Hello,
I checked with the code, the author URL is already added to the page and the Schema is validated without any warnings:
For Article schema, you need to paste the full HTML source of the page into the rich results test.
Hope this helps.
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.