Milk is Goaty and Goes Sour Quickly, What am I Doing Wrong??

I'll preface this by saying that I've only had my goats for about two months so I'm still very new to all of this. Previously, I have purchased raw goats milk from a few different local people, all who had Nubians, and it was never goaty and usually kept in the fridge for 2-3 weeks (on the rare occasion we forgot about it) without getting sour.

I have an Oberhasli currently in milk. We do not have a buck, and I do a mastitis test about every two weeks just for the heck of it (the kind on cardboard that you squirt milk on to). Our milk has a definite goaty flavor, and typically starts tasting sour in about a week, sometimes even just 5 days. I try to keep ahead of the milk so it doesn't sit that long, but sometimes life gets in the way and we just can't use it all within that timeframe.

I use seamless stainless steel buckets for milking, which are all rinsed with cold water before being washed with hot water and all-natural dish soap. I do a vinegar/hot water soak (regular old white vinegar as it is what we can get) 1-2x per week after the rinse, then wash as usual. The milk is put into an ice bath after filtering, sits in there for 30-45 min (sometimes an hour if we forget) before it goes in the fridge, which is maintaining about 39*.

Is there anything else I do to help fix this issue?? We don't mind the goaty flavor as it's not terribly pungent, but the souring issue is a big deal as it means about half a gallon (sometimes as much as a gallon) per week that's too sour to drink or use to make yogurt/ice cream/cheese.