In Mayotte 63% votes were against independence, while the other three islands were all >99.9% in favor. Wiki shows only the results but no explanation.
There will always be more to be said, but u/Silly_Crotch contributed a discussion of this problem a couple of years ago. While you're waiting for other answers, it may be worth checking this one out:
Why did Mayotte vote to stay in France while the rest of the Comoros islands voted for independence?