Hello,
Thank you for contacting Rank Math, and sorry for any inconvenience caused.
It appears your web server is blocking access to our API.
Please make sure to whitelist the IP 134.90.148.114 and the user-agent RankMathChecker/2.0.0; https://rankmath.com.
If you are not sure, please ask your web hosting provider to do it for you.
Once done, clear the SEO Analysis cache by going to Rank Math > Status & Tools > Database Tools > Clear SEO Analysis

Then, re-run the SEO Analysis.
Let us know how that goes.
We look forward to helping 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.