I have a rudimentry claro subtheme. This has been created with the sole purpose of avoiding some of the additional gumph that claro seems to add see https://www.drupal.org/project/drupal/issues/3332943
Anyway, recently after updating to 10.1.2, I have noticed another issue with the flex box layout when editing the node. Namely the flex grid seems to stretch beyond the size of the screen (safari os x). This results in making edit dialog boxes very difficult to work with etc.
I can override this by resetting the flexbox in my claro subtheme.
Please see attached screenshots