Product Display Issue ONLY with Internet Explorer 11 (IE 11)

-- url of the page with the problem -- : arhsvic.org.au/publications-sales/books
-- HikaShop version -- : 3.2.0
-- Joomla version -- : 3.8.1
-- PHP version -- : 5.6.32
-- Browser(s) name and version -- : IE 11

Hi,
We have a product display issue which ONLY appears with IE 11.In a two column display large spaces occur where a product should appear and the product containers appear to be of different size.
Display is fine with Firefox, Chrome , Opera.
In addition the issue ONLY occurs with one of our categories - Books.
Items for all other categories (DVDs, Newsrail) display just fine in all browsers.

Would love some guidance on how to deal with this issue.

Adrian