Did you modify the yaml before it started doing this? Kind of looks like perhaps an incorrect value on a column number or width line of the grid layout card.
For example, I have the following at the top of my mobile dashboard to force one column and a certain width (though it'd probably default to this anyway).
title: Mobile views:
- title: Home type: custom:grid-layout layout: max_cols: 1 grid-template-columns: 350px'