any known issues with Windows 10 15063 / 1703 Creators Update, Warhammer and Realtek HD Sound?

[alQamar]

Hi guys,
I have inspected a computer yesterday, that I have custom built for a TWC fellow and he expierences a very strange issue that affects only Warhammer*, but no previous Total War. SEGA Support is working on this case since weeks but to be honest not really helpful investigating the matter, just giving the usual first level advices, which did not help so far

I have checked everything and I can reproduce the issue on his computer but while having a quite similar PC my own (Intel chipset differs), the situation is not reproducible on my computer

Problem:
user expierences no ingame sound at all or just some sounds (ambience) AFTER starting any battle.
Before starting a battle sound is fine in the main menu and loading screen.
does only affect Warhammer*

What we have already tried:
no mods involved or subscribed
Steam game cache verified
uninstalled sound driver, reinstalled it, but it is different to mine (he has a original Realtek Windows 10 15063 driver, I have the Realtek driver (6.0.1.7910)
Quite unlikely, his Realtek driver cannot be changed (rollback, updated), we have tried both the one from Asus Support and Realtek itself.
we tried to alter playback rate (Hz, bitdepht) but no help
disabled all other playback / sound devices did not help (we tried his screen output or headset)
both are set to stereo in the driver and headset / screen so there is no loss possible because of that

A rare situation but I am on my wits' end here.

*I cannot get this is only limited to Warhammer as I suspect they use the same framework for sound playback at least since Rome 2.

[alQamar]

ofc
we also have renamed the folder in %appdata%\the creative assembly\warhammer