I omitted mentioning that this can happen on the Dual by-Pass, not the stand alone bypass which keeps the OEM filter in place and only siphons off a small amount of oil. Amsoil should mention this in the instructions.
This should not happen if the filter is at or lower than the stock filter location as the oil will not drain back, it will be at or near the lowest point.
I see many installations that are up in the engine compartment at the level of the intake. Those are the ones likely to give problems because of the increased time it takes for the oil to reach the engine . Instead of inches away from the bearings, you could be up to 5 ft or more depending on installation. The anti-drain back valve will hold the stock oil (if filter even has one that you use) in the filter but the hose will empty back to the pan leaving all that gap in the oil lines.