Default checked state is not appearing for coral checkboxes

"granite/ui/components/coral/foundation/form/checkbox"

but it's working fine for granite foundation one. i.e. granite/ui/components/foundation/form/checkbox.

I've tried many ways (e.g. checked (string) property setting as true, defaultChecked / uncheckedValue etc.) but nothing is working. One thing noticed that, "checked" property has type  ' booleanel ' while in JCR, only boolean is available;not the expression lang type. So,is it causing any issue?

Any pointers on this will be really helpful.