Dear JR_8989,
Good day! Thank you for posting to the Microsoft Community. We are happy to help you.
We understand that you are experiencing issues when exporting a SharePoint list to Excel, such as error prompts and missing columns in the Excel file. We're sorry to hear about the inconvenience this has caused.
Based on the screenshots you shared, it appears the issue occurs with number columns, both required and not required. We conducted a quick test and were unable to reproduce a similar situation on our end.
We have also researched the error message you provided. Please try using the "Export to CSV" option to see if it makes any difference. Additionally, refer to the suggestions shared in a similar thread for potential solutions: Why some of the columns are missing, when exporting to excel from - Microsoft Community
If the issue persists, it might be related to a background service that requires backend investigation. In this case, we recommend opening a support ticket with technical Support team. They can investigate the backend connection and provide a more permanent solution.
If you are the Microsoft 365 admin of your organization, you can follow steps in this article to contact Online Support. The support team has higher permissions than us and can remotely check the situation on your side, collect logs, and help you troubleshoot.
If you are not an admin, please refer to How do I find my Microsoft 365 admin? - Microsoft Support.
If the understanding above does not align with your issue, please feel free to post back and clarify.
We apologize for the inconvenience once again. Your patience and understanding are greatly appreciated. Stay safe and healthy.
Sincerely,
Rhoda | Microsoft Community Moderator