Hello,
Thank you for contacting the support, and sorry for any inconvenience that might have been caused due to that.
If you check other 404s on that stats page, you will notice they are all relative (without the domain name).
So, when you see a 404 on your main domain name, that actually means someone or a bot is trying to access your website at https://example.com/https://example.com
You can simply ignore this 404.
As for the traffic issue, can you please confirm if you are referring to our analytics dashboard? If so, please try rebuilding the index, then manually deleting old imported data, and start the fresh data fetch. Please follow these steps:
1. Head over to WP Dashboard >> Rank Math >> Tools & Status and click the ‘Rebuild Index’ button 
2. Head over to WP Dashboard >> Rank Math >> General Settings >> Analytics tab, and click the ‘Delete Data’ button and then click the ‘Update Data Manually’ 
3. It will start the new data fetch from Google. You can reload the page to see the notice related to the import process.
4. Once the process is complete. Please recheck the Analytics page.
Let us know how that goes. Looking forward to helping you.
Hey Jeremy,
You are correct in your assumption. I did what you said in your instructions and I’m still not seeing any traffic. Please let me know if you need access to the site to check it out. Thanks.
Hello,
Please follow this guide to reconnect and fetch the data from Google: https://rankmath.com/kb/delete-old-analytics-data/#num-4-remove-access-to-rank-math
Looking 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.