Hello Gloria.

The row width appears to be the same width to me, based on your screenshots. The content of the grouped row is not long enough to fit into the whole width of the table, but that's normal. If I misunderstood this, please explain in more detail.

As for the duplication of grouped rows, I can't say what caused this without checking the table. 

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.

Hi Gloria,

We are unable to reproduce the issue with our own data and also with your CSV data source.

1. We tried as table linked from CSV.

2. And we also tried when we import the CSV for a Manual Table, then made an SQL Query Table from it, disabled server-side option and enabled row grouping on the same column as your screenshots and we can't reproduce any kind of issue, the grouped row does not repeat.

You can try making tables on our Demo Sandbox and see how it works as normal on our Site.

You can download my Video demonstration, so you can see our test in more detailed steps.

Now, can you please check, does your table have this issue of duplicated Grouped rows maybe only on the front-end Page and the table on back-end works OK?

If that is the case, then you probably have a conflict for the front-end version.

wpDataTables is a WYSIWYG (What You See Is What You Get) concept-based plugin.

 This means that the table should look the same both in the back-end and in the front-end. 

If your front-end table looks and behaves differently than in the back-end, this usually implies that there is another plugin (or the current theme) that's changing the behavior of our plugin.

Can you please change the theme and see if the issue is resolved?

 If not, then please deactivate all other plugins except for our plugin, refresh the page where the issue is, and see if it is resolved (it should be).

 If it is, then start activating other plugins one by one, and after each activation refresh the page to see if the issue reoccurred. 

Once it does reoccur, you will have found the plugin causing the issue.

Let me know if you isolate a conflict with these steps.

Thank you.