Hi Karsten,
That option Ying mentioned only appears if the container block is a direct child if the Grid Block.
In your case, the container block is a grand child of the Grid Block (child of a column Container block inside a grid block). That is why the option isn’t appearing.
Here’s a suggestion:
Try duplicating the button. You then place the duplicate under the video.
You then add hide-on-desktop hide-on-tablet
class to the button’s container block for the button on the right column.
You then add hide-on-mobile
class to the button’s container block for the button on the left column.