I've seen this bug as well if you open up the code editor of the cards that are glitched, start from the top card, button etc... and just scroll through all those in the editor then close and save.
Once you reopen it should have fixed the glitch. I believe it is caused by the hypernext program during editing of a file or code and the glitch occurs there, cycling through the button and cards through the editor on the page with the glitch seems to fix it.