go to the Settings App, System Tablet Mode and change to don't ask and don't switch.
While this stops the tablet mode bounce, this is just a work around.
It's NOT a fix as it means I don't get to use my EXPENSIVE device designed and built by Microsoft for Windows 10 as intended (seamless transition into and out of tablet mode triggered by the hardware as it changes context). It also still constantly displays
the "auto rotate on" message every time the device falsely triggers the tablet mode event.
As the keyboard and mouse usually still work the entire time, it's especially frustrating to see this is still a bug as OBVIOUSLY the device knows it's still got a keyboard attached, even after the Jan firmware update. That's like 1 line of code...
if (keyboardAttached) { no, idiot, don't trigger tablet mode }