Hello Chris,
I guess you are redirecting to new page on clicking the RadToolBar button and RadTabStrip SelectedIndex is not preserved on the new page (which contains same controls as well). If that, the case, you need to set the SelectedIndex explicitly after redirecting.
One suggestion to set the correct SelectedIndex is by passing the index as url parameter when redirecting itself. The following code shows how to add url parameter when redirecting.
CS:
Now in the Page_Load event of NewPage.aspx, you can easily reset the RadTabStrip SelectIndex. Here is code snippet on how to perform this.
CS:
Could you provide some more information about your scenario, if that is different than what I tried?
Regards,
Princy