Screen Studio on MacOS won't record just the selected Window

I start a new recording with the Window option. During the recording, Screen Studio captures whatever is on my screen at any time, not just that Window's contents. Alt-tab or switch Workspace and that content is recorded.

That doesn't seem aligned with what record Window should do.

I have checked all OS level privacy settings and Screen Studio has been granted the correct ones, including Screen Recording.

Screen Studio Version 3.6.0-4214 (3.6.0-4214) on MacOS Tahoe 26.3.1 (25D2128).