Hi,
the missing line seems to be a Max bug. But the daylight system works and the sun is actually connected. When I create a new daylight system (Max 2023.2.2), the line is missing here as well. I never done it in Max 2023 until now because I have one in the startup scene, created with an older Max version - so I never noticed.
As for "washed out", you are using the tone mapping stack wrongly. Just move photographic exposure on top of the stack and use reasonable photographic settings, matching a daylight situation.
Good Luck