When a USB key report has a modifier + a key code, and such a modifier was not previously reported, then the modifier gets ignored.

The issue does NOT occur in libinput 1.9.2, only since version 1.9.3

e.g.
    Key report with modifiers:  00000010 (Left shift) and keycode 0x04 (a)

    Expected: "A" (uppercase/shifted letter A)
    Obtained: "a" (lowercase letter a) - Left shift modifier gets ignored

This doesn't occur for all modifiers and all combination of letters. For instance a pre-shifted "b" does output a "B" as expected, but fails for "d", "e", etc.

This will hardly occur under normal conditions of course, the issue arises when using a keyboard that attempts to send "pre-shifted" keys to allow symbols typing on a single keystroke (without holding shift).