ePub loses all my rounded corners on pull-quote text boxes...

I am trying to ePub a book I set up that has a pull-quote text box in each chapter with rounded corners. Publishing to PDF works fine and all is well. ePub however gets it wrong. Including a picture here. The left is how it should look. The right is what it becomes upon ePub. I'm stuck for a solution... Anyone?
(InDesign 15.0.2   ePub 3.0)