Was the "last" update which supposedly caused this a sonar update or a Windows update? Because if it was a sonar issue many people would have complained including myself but I do not see this.
You need to trace the root of the cause, so i'd try recording with another application (I'm sure you got one) and/or another MIDI interface (some of your synths that may communicate via usb MIDI or get a 20$ midi to USB cable) ... do a loop back of a midi ping and see how it aligns with different apps/interfaces
BTW I actually returned a pro label MIDI interface because it was giving too much jitter and offset under win10 and went with a cheaper one which is much steadier