OVERFLOW

When you're using a Fixed Height on a Frame, and you add sufficient content that it overflows the height of the Frame, then you'll want to determine the the behaviour of the overflow. You can make the content overflow in three ways: 'Visible', 'Hidden', or 'Scroll'.

Overflow is located in the ADV (Advanced) Tab.

VISIBLE:

Content is not clipped and therefore overflows into the frame below.

HIDDEN:

Content is clipped and therefore the content that overflows will not be seen.

SCROLL:

Content is clipped and a scroll bar is added so that the rest of the content can be seen.

TOUBLESHOOTING:

Notice in the video above, that in the 'Visible' column, the text was only visible to the extent of Parent Block. If in the event that you'd actually want the text to be visible, you could make the the Parent Block a Fixed Full Height, then, you could set the height so that it only applied to Desktop Only.

As a further Troubleshooting exercise, you could even make the child a Full Height too. 

See the video below...

MORE TOUBLESHOOTING:

As a Pro Designer, you'll also know that you could override everything above and apply a max height to your columns, then set the Parent to Equal Height Columns, but then you'd just be showing off!!