Server error (5xx) These pages aren’t indexed or served on Google

Hello,

Thank you for contacting Rank Math Support. We are sorry for any inconvenience you might have experienced using our plugin.

Do you mean your site stopped working? If that is what you mean, we can’t replicate the issue on our end as your site works fine.

We have checked your sitemap and robots.txt file and they are set correctly. If there are any issues reported on your URLs that prevent them from being indexed or affect your rankings, then you should see them in the coverage section report of your GSC:
https://support.artlogic.net/hc/en-gb/articles/360016851260-Google-Search-Console-errors-and-coverage-issues.

Also, 5xx errors are usually caused due to server misconfiguration or other server issues. Can you please share the website error log with us? Having the error log file will give a clear idea of why this might be happening.

Concerning your last question, you can review the steps here to fix the issue: https://support.google.com/adsense/answer/12171612?hl=&sjid=14980403504066303682-EU&visit_id=638322930311155101-3134305474&rd=1

Let us know how this goes. Looking forward to helping you.