Site navigation appears in group banner incorrectly, in a new group - bug, or config I can fix?

We moved to V12 a few weeks ago, and I've created my first new subgroup at the site level. The group banner color is surrounding the site navigation, and this is not the intent. Is this a new setting in V12? Other groups don't look like this.

Group banner for a group that was created before we went to V12:

Group banner for a group created today:

This is the theme options setting for the new group:

If this is a bug and I need to submit a ticket, I can do that...but I'm wondering if there's some setting I need to change that was reset to "factory settings" when we went to V12.   or   do you have insight on this? Thanks!



Edited question text.
[edited by: Sherri Vance at 3:54 PM (GMT 0) on Mon, Aug 16 2021]