media – Updating to Drupal 9.1.0 reduced the size of remote video thumbnails in views. How to resize them?

I have a view which displays a selection of remote video media in a grid using the oEmbed format option. Updating my site from 9.0.9 to 9.1.0 caused all my remote video thumbnails to shrink to 200 x 113px which is far too small on a desktop. I don’t know what size they were exactly before the update but I want to make them larger again. I have added max height/width dimensions to the remote video media type’s display manager and this has successfully resized the thumbnails of videos added to simple posts using the “insert from media library” button, however this has made no difference to the thumbnails in my view.

Please can anyone help? I can provide a link to the view if that helps.