Well well, isn't that a surprise ^^
Was just about to mention I've never had any nvidia driver problems untill yesterday, which was weird as I've been using that driver for several weeks without problems as well. No idea how it suddenly, without any sort of update, caused sound issues in the game and even in the lobby. Just reverted back to driver version 457.09 using the driver's "clean install" function which fixed everything for now.
Still good to see it's getting solved the proper way.
I'll keep this driver install as backup though