TabStrip Persist Content
By default, the content of a Tab is rendered in the DOM when this Tab is active. Once it is deactivated, its content is disposed and re-initialized again when the user selects the corresponding tab.
To keep the Tab content in the DOM at all times, set the PersistContent boolean attribute of the TabStrip to true. In this way the inactive TabStrip content will be hidden with CSS.
Persist the TabStrip content
<TelerikTabStrip PersistTabContent="true">
<TabStripTab Title="First">
First tab content.
</TabStripTab>
<TabStripTab Title="Second">
Second tab content.
</TabStripTab>
<TabStripTab Title="Third">
Third tab content.
</TabStripTab>
</TelerikTabStrip>