I'm also having trouble getting my tag line to display on mobile devices. I got it working fine with some code in Page Content > Settings > Advanced code, but as soon as I purchased the plan it stopped working (because apparently you need a Business or Commerce plan to customize code from there?).
So I tried putting the code into the Custom CSS under Design, but it wouldn't work.
Here's my site: https://flugelhorn-smilodon-b9f6.squarespace.com/
Is there any way to get the tag line to display on the Personal Plan?
