Hi, I'm having a related problem -- my mobile product page was working fine, with 2 product columns displayed (using the outdated CSS), until suddenly it wasn't. The products were now displayed in a single column.
I've tried various CSS fixes including the above, and also tried the new feature recently added in the store section settings. While these fixes got me back to 2 columns, they all resulted in tiny product images, whereas before, the images -- even in 2 columns -- were much larger.
Any ideas? Thank you --