Maybe not a useful comments: but what does the udev see ?In /dev/input/by-id/ you should have all the symbolic symbols of the input devices to their input sources. Did it changes between the 2 versions?
Also check if distro didn't banned some input device node creation at udev. I saw it at least once for my keybord so I don't know how frequent this is done in the wild.
Hoping that it reduces investigations a little. Cheers
