Oop, sorry I guess that’s not the same issue. Mine is in the Cards Management, but inside the cards themselves:
See on the right side of the window there are two scrollbars. I started noticing it maybe ~2-3 weeks ago? I only see it on the Back preview, I guess because it has more information than the Front.
I only use Chrome browser, but I see it in both Windows and Mac OS. I don’t see it in mobile.