"No Results" in Device Posture checks

I need to require WARP for my application access. However, it seems that WARP client doesn’t perform device posture checks for some reason and thus I get a “Forbidden” error page when trying to access my app.

The following image shows the added WARP check and the result I get when checking a specific device posture check:

Is there a step that I missed to make the client perform the check? Or is this simply not possible for the free plan?