Hi, louban,
First I would check if your object has this attribute filled. So after you would enter such object, check the checkbox and click Finish-submit, re-enter such object and find your checkbox value in "Anvanced view".
If you see it there it means it is correctly propagated and not displayed in RCDC. If so, check if you have Mode=TwoWay in properties.If you don't see this check box checked either your rcdc doesn't propagate attribute to FIM service or you have a
workflow that is cleaning the checkbox.
Please do the following: create such object, open it once again and check the checkbox and take a screenshot of latest entries in "search reqests".
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