Tabsheet containing BrowserFrames

I have a TabSheet which has a BrowserFrame in each tab.
I notice the following undesired behavior: When I change the tab by clicking on it, the browserframe reloads, possibly erasing any inputs the user might have made in that tab.

How can I keep the tab from reloading?

That’s a feature of TabSheet - the contents of a tab are not kept in the DOM when you switch to another tab. You’d needs some kind of custom implementation to get around that.