You could use Flexbox instead of rows with parent div set to Align Stretch then the two columns for social icons will stretch to fill the vertical space.
Nothing wrong with sticking to the way you’ve done it though. The reason you’re getting the line is because the row symbol for social isn’t wrapped in a Div as it is on the homepage, this means the left column is showing the light background from behind as it doesn’t fill the same height as the right column. Checkout your homepage navigator (where it is correct) to see the difference in structure of the other pages…
If you move the symbol for ‘Social’ into a Div Block with the class you used on Homepage (Content. Footer) then it will work. Personally I would remove the symbol you have created and set it to the parent div Content.Footer and then add back into each page.