Hello,
Thank you for your query and we are so sorry about the trouble this must have caused.
There are two canonical tags on your website. The first one is added by Rank Math with the correct URL. The second one is added by something else with an incorrect URL causing the issue you’ve experienced. See the screenshot in the sensitive data section.
To fix this issue, you’ll have to identify if there’s another plugin or if your currently active theme is adding that second canonical tag. You may refer to this guide to help you with that: https://rankmath.com/kb/check-plugin-conflicts/
Only the site admin would know and your users won’t be affected by this troubleshooting.
Let us know how that goes. Looking forward to helping you.