I've built my survey using Connect and successfully published to my ArcGIS Online account. When I make design changes (add a photo to the background, change the color from default green to blue, customize the thank you screen, etc) and hit "publish", it tells me that it was "Published Successfully!" But, when I open the survey in my browser and via the Survey123 smartphone app, none of the design changes are there; it's back to the default settings.