I suspect you should find out from the dairy if you have a contact number and/or address for them... ask them.
You are describing issues with the milk that I have absolutely no experience with.
All I can add to what I have already stated is that what the goats are fed and/or get into can also affect the flavor of the milk. Breed can also make a difference... however that is mostly in nutritional value, which could affect flavor some, and butterfat content.
I hope you find your answer. Otherwise, you may have to find an alternative to what you have available.