Hello Tony.

I can't replicate this issue locally.

Please provide me a temporary WP-admin (administrator) user for your site where this happens, so we could log in and take a look ‘from the inside’ as that’s the most efficient way to see and resolve the issue. 

We do not interfere with any data or anything else except for the plugin (in case that’s a production version of the site), and of course, we do not provide login data to third parties. 

You can write credentials here just check PRIVATE Reply so nobody can see them except us.

Thank you Tony.

The issue is caused by the origin header (the header from the Google Sheets file):

If you modify the headers in your Google Sheet:

It will work correctly in wpDataTables:

If you're not using the Google Sheets API, please note that it may be up to 20 minutes before the change made in Google Sheets is applied to wpDataTables.

You're welcome, Tony.

Let me know if there's anything else I can do to help.

That depends on a lot of things, Tony.

If you're not using the aforementioned Google Sheets API, and the table is large, it will take time for it to load. Even with the Google Sheets API, it will not be lightning-fast, but it should be faster. You can also try the (relatively) new caching feature.

If the table is not that big, and you're facing issues with the loading speed, it could be related to the server - how much memory you have on the server, how much data you have on the site, etc.