I agree - the grid feature isn’t great. I normally just default to flexbox - the grid is a pain to control and I found that it doesn’t work properly in IE anyway. So there isn’t much point in it.
In fairness to the grid, I managed to solve the problem - a very odd one: the images in the first column simply didn’t show. When I converted it to a flex box, those images still didn’t show, so I replaced them and it worked. All classes were the same.
Sometime, I can’t be bothered to solve a problem, after all I am paid by the hour!