Can someone help me work this out

Site URL: https://www.rewindcinema.net/coming-attractions

What the hell is Squarespace doing. I want my site to look good on laptop and phone. The first gallery on my website is using the new 7.1 gallery grid. Had to add code just to change the font size of the title. Does anyone know why when it opens in a phone browsers the images stay next to each other in a three column row like on the laptop browsers? Shouldn't it automatically reconfigure to make the images bigger like in the bottom gallery? Which is using the 7.0 indiviual image placeholders. The problem with this option is that the order gets all jumbled up when looking at it on the phone. Ugh I'm at a dead end with this. Any help will greatly appreciated. Sorry it's late and i've been up for a long time trying to fix this. 

Hi.

You want

Change 2 images/row on mobile to 3 images/row, same as on desktop?