I think 9 months is about the time separation anxiety tends to appear even in babies who were friendly and confident before, so you're at a rough stage - it should get better! Meanwhile, I don't know how you are picking/finding your care giver, but finding someone who has experience with babies should help them have the patience to let your little one get used to them! You might have to leave the house or close the door for a few times and resist going back in to "check" so he settles down... :( Good luck!!
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