I'm having the same issue outlined in this thread (unfortunately couldn't reply to it or get a working solution from there)
https://www.prestashop.com/forums/topic/370354-2-product-columns-for-mobile/
That is, I'm trying to display products per row when viewing on a mobile and changed the product-list.tpl from col-xs-12 to col-xs-6 to achieve this. Unfortunately, when viewing on a mobile, some lines will only display one product instead of 2, leaving an ugly looking gap.
The problem seems to only happen when on rows below where the product on the left has a longer description or is an extra line longer than the one on the right. Problem only occurs on mobile phone (Nexus 6P), it's fine on tablet. Problem can be recreated on desktop by squeezing browser window to narrowest setting.
Greatly appreciate any solutions or workarounds anyone has. I'm using Prestashop 1.6.0.8 Default Bootstrap theme and webpage with issue is below:
http://simplysmoothskincare.com/store/45-le-mieux-skincare