Flight Sim / Game Pass / 3rd Party Controller - why is everything so difficult?

I want Flight Simulator but was not sure my kit was compatible, so rather than buy it outright I saw it was available on GamePass so I thought I would sign up and try it.

Have a number of devices, but to start with, I have a Microsoft Surface Pro X running Windows 11 Home and thought I would try it on that. I signed up for Game Pass and got nowhere, so upgraded to Ultimate and that did not help much, so next step was to buy the game outright (discounted as I have Game Pass) - I assumed this would give me a download option, but apparently I have to do this through the XBox app....

The app wont let me do anything as it says I have no controller attached - I do have a controller, it is wired (usb) and is a 'DOYO Wired USB Gaming Controller Gamepad Joystick' and works fine with the PC but the XBox app does not see it.

Am tearing my hair out trying to do a really simple thing which is to download and run Flight Sim - what am I doing wrong and why does MS make it all so hard?

:)