After downloading the latest FS2020 version 1.12.13.0, I have an issue with my PFC serial quadrant. After the sim is started and the PFC driver activates, detecting my quadrant, it initially works well. I can move the throttle to set full power and takeoff for instance. Then, at a random moment later, nothing works on my serial quadrant. If I restart fsuipc, the PFC driver does not detect anything anymore. If I restart the sim, it does not work better. I have to restart windows to make it work again.
Note that on the same machine, I also have P3D installed. I have zero issue there, meaning that the quadrant and the windows COM driver work well on this PC. I had also no issue with the previous FS2020 version.
If my quadrant fails in FS2020, it will also fail in P3D if I try just after the failure. It's as if the COM driver was impacted. I have to restart windows to fix it.