Thumbnail size scaling issue

Hello,

first of all thank you for providing this amazing plugin to the community, I really appreciate it.

I have two questions but will start with this one concerning thumbnail size.

Somehow the size of video thumbnails do not adapt to the full size of the potential column image size, its not scaling.
I have an example image uploaded for you here.
https://www.bilder-upload.eu/bild-a2b45f-1587658998.jpg.html
If I have two columns the image does not expand full size and there is always this grey frame.
with four columns its not an issue, but starting with three, down to one its not working properly.

Can you help me with that?
thanks a alot!