Same issue. I put one little bit of custom CSS in the custom CSS editor, but the change only shows up when I am in the Design/Custom CSS part of the Squarespace menu. All I'm trying to add is some shading behind the text on my homepage. It shows up when I'm in Design/Custom CSS but then goes away when I return to the main menu, even after saving. Can anyone help?
Page url: https://www.themichellecowan.com/
CSS added:
#block-d6b457e24091aa47165d{background:#61616161;padding:50px;text-align:center;}