As you can see, the list-items in the first row have same height. But items in the second row have different height
If you know the items you are mapping through, you can accomplish this by doing one row at a time. I know it's a workaround, but it works.
For me I had 4 items per row, so I broke it up into two rows of 4 with each row height: 50%, get rid of flex-grow, have and in a flex-column. This will do the trick