Unmounted tab not getting validated

[gpadbidri]

I have a REDUX Form where on section is TAB based. These Tabs get enabled / disabled based of some selections.

Example:
I have 4 Tabs of which FIRST Tab is MANDATORY - Till here we are good
Tab 2, 3 and 4 enable / disable based of some other choices.
My Issue - If Tab 2 is ENABLED ONLY then it should be REQUIRED else it should not

My observation -
I have used Field Level Validation.
Tab 2 when mounted (i.e. when Tab 2 is Active) I see the fields registered in SYNCERRORS and they disappear as soon I switch the Tab. and hence the form gets submitted.

How do I handle this ? Or if this scenario cannot be handled by redux form ?