Hello,
Mode 68 relies on the sync tooth staying within the bounds of two ref teeth which is extremely unlikely on something with 36 teeth so your timing is very likely to jump around as the revs climb.
Change to mode 7 and take the spark plugs out and unplug the injectors. If it syncs with no errors with the plugs out then this is a Tooth ratio tuning issue. You need to put the plugs back in and change the Tooth Ratio by 5 (then reset the ECU) and test.