WP 5.9 Gallery Block Issues

I have an image gallery in all of my posts with images set to not cropped, thumbnail size, 3 or 4 columns.

If I look at an old post (anything before the WP 5.9 upgrade this week), the gallery images look fine. If I go into that old post and update it (without changing anything in the gallery), the gallery images change to stretched in safari and full-size, singe column (instead of thumbnail, 3 or 4 columns) in chrome and firefox.

Also, newly created posts are having the same issue since WP 5.9 upgrade.

Issue is present while using either GeneratePress or Twenty Twenty-Two themes.

I have tried deleting gallery and re-adding, same issue.

After rolling back to 5.8.3, all updated galleries are corrupt, can’t be recovered, and need to be recreated.