I’ve experienced what you described in your initial post—the mobile device screen showing a 3-camera group but tapping one camera refreshes the 3-camera group instead of selecting into that single camera’s Live Stream—and have been able to reliably duplicate it: When I’m looking at a Cam v4’s Live Stream and tap to activate PiP, the new PiP floating window can be enlarged and can appear to be another full instance of the app that has been spawned (looking at open apps shows two Wyze app instances running at that point), but if I try to tap one of the cameras showing in a 3-camera group in that new “instance”, the behavior is what you described above.
Weird.