I asume you are talking about Bixa orellana, or the cabbage tree. I belive they are evergreen, being tropical, so it is likely the main reason there dropping leafs is because there adjusting to coming inside from outside. This is caused when a plants leafs are no longer able to work properly in a changed enviorment, so they drop the old ones and put out new, better ones for working in that enviorment. Make sure the seedlings still recieve good (but not direct) light.
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