Windows 11 touch keyboard doesn't work when external monitor connected

Windows 11 Home 24H2 build 26100.4770

This post is less about me asking for help (I'll find my own way around it that works for me) and more about reporting some frustrating and frankly embarrassingly basic usability issues that if someone would have taken 15-30 minutes to test would never had made it into the wild.

I have a Lenovo Yoga 6 (a 2-in-1 laptop/tablet) and I wanted to use it in tablet mode laying on my desk connected to an external monitor. This allows me to use the pen for note taking while I have other things showing on the external monitor. Sometimes I need to be able to type things on the external monitor. In tablet mode there is no keyboard attached: only an external monitor, a bluetooth mouse dongle, and the power cord. Almost everything works fine.

When switching between laptop and tablet mode "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\PriorityControl\ConvertibleSlateMode“ properly switches between 1 or 0 even if an external display is attached.

Setting "HKLM/System/CurrentControlSet/Control/PriorityControl/ConvertibilityEnabled" to 1 made zero difference.

When I plug in an external monitor the touch keyboard stops working properly no matter what it's set to ("when no keyboard attached" or "always"). It won't show up period unless manually invoked with the system tray icon (which has to be enabled first). I expect this when NOT in tablet mode (a keyboard is attached). But I do not expect this behavior when in tablet mode (no keyboard attached).

So, I did a little research and found out that the ability to manually switch between modes was removed so that's not an option (that would have fixed all the problems that I'll describe in this post). Worse still, the help article located at the following URL does not describe how Windows actually behaves: https://support.microsoft.com/en-us/windows/turn-tablet-mode-on-or-off-in-windows-add3fbce-5cb5-bf76-0f9c-8d7b30041f30#id0ebd=windows_11

That article doesn't say anything about exiting tablet mode when I plug in an external monitor but that appears to be exactly what it's doing. It's fairly easy to test all you have to do is put the laptop in tablet mode, wait for Windows to switch, and then plug in an external monitor. Less than 5 minutes and we got a glaringly obvious problem.

A way around that is to enable the setting "Settings -> Personalization -> System tray icons -> Touch keyboard" and then I have to manually activate the touch keyboard when I want to use it. Much less annoying but still less than an ideal situation. How many non-technically inclined users do you think out there would even bother figuring that out? I hope zero because it gets even more frustrating after that. You would think that would be the end of these unusual usability problems but it's only the beginning.

If after all that I then select a text input field on the external monitor with the wireless mouse, and then tap the taskbar icon to manually open the touch keyboard (on the primary, touchscreen monitor), instead of the keyboard showing up on the only touchscreen attached to the computer, it instead pops up on the external monitor where the input field is.

Ok so it does makes sense that the keyboard would show up on the screen that contains the text input field from a programming perspective - but from a usability perspective it can create a very frustrating experience when certain conditions are not checked.

Here's the situation: I have no keyboard attached and a touchscreen attached to the computer do you really think I want to use my mouse to type on the touch keyboard? Shouldn't the touch keyboard favor a touchscreen if one is attached? The current behavior only really makes sense if there's no touchscreen or keyboard attached to the system. What if there are multiple touchscreens attached to the system? How do I set which touchscreen I want to always use?

Ok so the keyboard is on the wrong screen, and I think ok I'll just drag the touch keyboard from the non-touchscreen to the touchscreen and start typing there. Sounds good right? It is, until you start typing. After I press the first letter on the touch screen keyboard, it immediately moves itself back to the wrong screen ... sometimes. Sometimes it decides to stay where I put it and sometimes it just moves itself back to the non-touchscreen, external monitor. And there's seemingly no way to lock it to one screen. And that happens every time you decide you want to type something on the external monitor.