Hi! I'm very happy to find this forum!
There is now a second Adjust Width link in Template Designer for all templates that use the first CSS bundle (https://www.blogger.com/static/v1/widgets/3645911276-widget_css_bundle.css). If I change to the second CSS bundle (https://www.blogger.com/static/v1/widgets/3375562265-css_bundle_v2.css) by adding b:version='2' class='v2' to the HTML tag the problem goes away in Template Designer but all my margins, widths, and paddings are off. The Advanced link now does almost nothing except turn to bold when clicked on and the second Adjust Width link does what the Advanced link used to do.
A lot of template designers prefer the first css version but this will be confusing the the recipients of the templates. If I find how to fix it I'll post here and I hope others will too!