Alan,
I believe you have silicone contamination. You can wash down your stripped surfaces with "silicone wash" which may help. I've had some for years which I purchased from Mohawk. I'm not sure of a good source now but I know it is available. When you apply your top coats, you may have to add fish eye remover depending on what your top coat is. Silicone isn't usually a problem with shellac.
Craig