Input Action mapping single key always stucks combo keys with ctrl alt shift + samekey

Development Programming & Scripting Blueprint
1

I got 2 input actions like B and Ctrl+B:

20210318165812.png

I listen for input in my widget:

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20210318165844.png1201×540 59.7 KB

But when I press Ctrl + B, I only got “B” output, Ctrl + B will never be triggered. I suspect it’s something about combo keys capturing priority.

How to make Ctrl + B triggered and B not triggered? Thanks.