Well today I tried something different. I uninstalled the tools and yamaha USB driver, rebooth, and then I rolled back to the previous tools/driver installer v 2.16. Reboot, open Nuendo, open Yamaha USB driver ASIO settings, obviously the drop down menu with the various settings (aka lower latency/stable etc) is gone. I choosed the lowest buffer. Noticed that this driver doesn’t go as low buffer/latency as the newer, with wich at first I was getting down to 2ms or so, stable operation. Anyway I choosed the lowest buffer setting (64 samples), giving me a latency of 5.261ms, still not bad. I then loaded the same session, no dropouts at all, stable playback at the lowest buffer setting. Now, at the begining, the newer driver with the drop down menu was giving me excelent, stable performance even at the lowest buffering settings, and I remember I started getting the dropouts after windows did some update, so there must be something that was added to that driver, that with a windows update got screwed up. I’m going to keep working with 2.16 tools for now, because 2.21 at the end was giving me dropouts AT ANY BUFFER SETTING, not just low buffer settings, it was very unstable. I did enjoy whatever that driver had to lower even more the buffer settings, I hope Steinberg can find whatever went wrong.
Just want to note that the performance meter was never pegged, the load was very small, and I still was getting dropouts no matter what buffer setting I choosed. Also remember that I also tried switching to my eleven rack ASIO driver and Axe FX, both at their lowest buffer setting and the droputs were gone and everything was smooth sailing.