Hi guys
I recently noticed that if I try to lower my buffer size lower then 512 I'm getting no sound in Cubase, I tried every trick and optimization technique there is, I was used to work with 512 because I never tried to change it.
Any Ideas?
Every componet is updated to the last driver including Win updates.

4770K OC 4.1GHZ
32GB RAM
Asus Z-87-K MOBO
Win 10 64bit
Cubase 9.5.3
RME HDSPe AIO
ATI HD7750
Sonarworks Reference 4