Opening mat-expansion panel is moving the opposite column, how to keep it still?

Question

In my project I have two columns, each with their own mat-accordion which holds some mat-expansion panels.

When I click to open any one of the expansion panel

Answer 1

Just like I guessed. You're row content is being align to the center. Change the align-items to for example flex-start to align the row content to the top of the row.

.row {
    ...
    align-items: flex-start;      
}