This is because you're using the Columnize feature. It's only good for text. Though it displays Envira Gallery, some images will be cut-off in Chrome. It does not in Firefox because each browser engine has different methods of display.
I'd first recommend that you create a Global Block with 2 columns and move your text and grid separately to each column then paste the global block's shortcode in the Accordion Item content.
If that does not work, I'd recommend not to use an accordion for this case. Please use a section with 2 columns instead.