Hiya all.
I'm in the process of actually building a dedicated sim now at home. I've used FSUIPC for years too, but been away for the past couple of years. Anyway, long story short, I have the latest version of MSFS, and I have PMDG 737 700 and 800 installed. I can see in FSUIPC that there are supports for these aircraft.
I am building a FMC, I've 3d printed the box, buttons etc - everything I need, and am using a Leo Bodnar BBI 32port switch box. I've tested a Microswitch in Windows 11 and in FSUIPC 7. It's recognized just fine. However, when I assign it to 737 Left FMS letter a, pressing the microswitch fails to have that letter show on the FMS in the 737 800.
I've come across some other issues with FSUIPC - such as the fuel idle / cut off. The "details" are there for the assignment but when assigned, they do nothing in the sim. Am I missing something?