I would not be so quick to merely blame the drivers. Careful with that “rationalization machine” we call the human brain! It can follow many a red herring to mistaken assumptions!
To ensure you do not waste your investment in those three Ultralite’s, give MOTU tech support a call. They are always very helpful, even if it sometimes takes a few calls to figure everything out. They are all good, but I seem to work with Travis the most.
9am - 6pm ET, Monday - Friday
At least you’ve eliminated that Windows “sounds” haven’t been messing up your audio by forcing the sample rates to change, what with disabling the MOTU Audio Wave for 64 bit driver.