Adobe InDesign Export to ePub3 does not reflow in Digital Editions...why!

I exported an InDesign CC 2015 document to the ePub3 format to view in Digital Editions 4.5. Included was roughly 5 pages of text. The text did not reflow beyond 1 page... it also would not reflow to the split screen format though it showed a page count at the bottom of the screen for 5 pages. Conversely, an export to the ePub 2 format seem to reflow correctly. Tried checking the settings in the Export setup, but have not been able to make this work. Please help!