Try reverting your soundcard driver to an earlier one, or get the latest whichever applies.
Or even disable your soundcard and use the onboard soundcard to see if the same timing anomalies occur.
also try to do the same recording technique with the buffer size at MAXIMUM. Do the MIDI notes move earlier than the 8 msec they are now (1/64th note at 120 BPM)?
On some recent cards using a very high buffer rate can increase instability in the card or driver.
Try adjusting the ppqn rate in Preferences.