Comment # 7 on bug 1173116 from Takashi Iwai

(In reply to Ludwig Nussel from comment #4)
> CPU family:          6
> Model:               78
> Model name:          Intel(R) Core(TM) i7-6600U CPU @ 2.60GHz
> Stepping:            3

This is indeed the CPU model hitting a buggy firmware.
Try to downgrade the ucode-intel to 20191115 of Leap 15.1 until the fixed
(reverted) package is released for Leap 15.2

If you still see the same problem even after the ucode revert, please reopen.