Thank you for contacting Rank Math and bringing your concern to our attention. I’m sorry for any inconvenience this issue may have caused you.
Meanwhile, assuming you are using the latest version of all the plugins and the themes (please update if not yet), this could be caused by conflicting plugin/theme on your site.
To determine that, please follow this troubleshooting guide:
Here is a video you can follow as well: https://www.youtube.com/watch?v=FcIWRhcUP2c
Only the site admin would know and your users won’t be affected by this troubleshooting.
Let us know how this goes.