the ambient lighting tends to go off during the day. It's an automatic feature to save energy and because it's less effective in daylight. There isn't a setting to keep it on all the time, but it's designed that way to enhance visibility when it matters most.
Have you tried rebooting the system or doing a hard reset? Sometimes that clears things up. If that doesn't work and you've already tried adjustng the settings, I'd reach out to VW support. They might know of a fix or need to do a software update.