netflix on my macbook air i just bought 3 days ago won't work. but netflix works on every other apple device. what do i do?

i just bought this macbook air, and all of the sudden, it won't play netflix and when it does, it constantly glitches. Netflix isn't the problem because it works on my brothers macbook air that he just bought 2 or 3 weeks ago and it also works on every other apple device i have. please help i spent a lot of money on this and would be devastated if this is unfixable.