Hello,
Thank you for contacting the support.
That is the Frontend Stats Bar that we released in one of our recent updates. This bar shows you the statistics of your current post/page so that you do not have to change tabs to check that. Here’s a guide with more details: https://rankmath.com/kb/analytics-stats-bar/
This bar is visible only to the logged-in users and the visitors of the website would not be able to see it.
It seems like the bar is not loading properly on your website. You can follow this guide to determine if there’s a plugin/theme conflicting: https://rankmath.com/kb/check-plugin-conflicts/
However, if you wish to remove that bar completely, please click on the x button on the top right corner of the bar. You can also disable it from Rank Math > General Settings > Analytics:

Hope this helps.
Thank you.
Thank you very much. very helpful.
Hello,
We are super happy that we could address your concern. If you have any other questions in the future, know that we are here to help you.
If you don’t mind me asking, could you please leave us a review (if you haven’t already) on https://wordpress.org/support/plugin/seo-by-rank-math/reviews/#new-post about your overall experience with Rank Math? We appreciate your time and patience.
If you do have another question in the future, please feel free to create a new forum topic, and it will be our pleasure to assist you again.
Thank you.