Game lags badly for the first time ever since latest patch

Elke87  What exact motherboard do you have?  I'd expect it to offer at least one audio driver newer than 2015, or for a compatible driver to be available from Realtek.  If you list the make and model, I can take a look around.

You can also try other sound devices, as some may come with their own drivers.  The Realtek driver might still interfere, so consider this an experiment more than a guaranteed fix.