I believe you. I’ve reinstalled the same (4.2.2) version of Qubes half a dozen times in the past week and I’ve seen different USB-related behavior on the same ThinkPad.
Trackpoint sometimes worked and sometimes didn’t. In one attempt it worked at first, then after a reboot it didn’t. In another it was the other way around.
Presently it consistently doesn’t work and I’ve rebooted 2-3 times. Luckily, at least one of “equivalent function” peripherals (Trackpoint, touchpad, mouse) always works, so I haven’t been pressed to investigate.
There’s a tip here on improving the behavior of Trackpoint which I haven’t tried as I’d rather not touch anything now that I don’t have any major problems (and Trackpoint doesn’t work in the first place, so I’d first have to troubleshoot that).
Maybe it’s still “either that or the other one”. You have the other one.