FSX - FMC Touchscreen calibration in Windows 11 (tablet PC settings no longer exist!)

hi there
Due to the motherboard of my existing PC running FSX dieing on me, I have been forced to buy a new PC and reinstall FSX. I have been able to reinstall all my external instrumentation (pedals, radio panels, yoke etc) successfully - the one thing that is still giving me problems is my FMC.
I have a three screen set up: one main monitor, one secondary monitor for PFD / MFD popouts and a third Nixdorf touchscreen monitor (800x600), where I have placed the FMC to be able to program the FMC by touch without having to use the mouse. All worked fine under Win10. Now in Windows 11 the monitor works and accepts touch inputs, however the actions are carried out on the main monitor and not on the touchscreen / FMC itself. Searching high and low in the control panel / settings but now Microsoft have removed the "Tablet PC" settings from Windows altogether there is no way I can see to calibrate the touchscreen at all and define that monitor as the touchscreen as was previously easy to do in all previous Windows versions.
I have tried defining the touchscreen as the main monitor, which does the job initially until I come to start a flight. After scenery load etc, the screens goes haywire as FSX doesnt like trying to load onto a screen with 800 x 600 resolution, and I have to abort the session. I figured that if if I could get that to work I can just move the main FSX screen back to the large monitor, and drag the popout FMC back to the touchscreen. No luck.

Has anyone else come across the same issue and has a solution (or ideas?)