Wow, that's strange... I tested again and zeroing the yy bytes in the regular Wiimote doesn't change anything (it still works fine), however, zeroing the yy bytes in my Wii Remote Plus made the "invalid packet type" errors popping again. Maybe it's something specific with the very first units of Wii Remote Plus (the non-TR ones)?
Avell A70 MOB: Core i7-11800H, GeForce RTX 3060, 16 GB DDR4-3200, Windows 11 (Insider Preview)
ASRock Z97M OC Formula: Pentium G3258, GeForce GT 440, 16 GB DDR3-1600, Windows 10 (22H2)
ASRock Z97M OC Formula: Pentium G3258, GeForce GT 440, 16 GB DDR3-1600, Windows 10 (22H2)