How long ago was that? Perhaps earlier iterations of Hue bulbs weren't as reliable.
The really big advantage for me is that I have all of my downlights bound directly to the switches that control them (Inovelli blue series), so they'll work even if the Hub takes a dump. Which happens now and then.
I guess that was a few years ago - I mainly use Hue bulbs in my lamps around the house, everything else is controlled via z-wave relay's or dimmers.
That code is grabbing the next sunrise time that the hub calculated at the last sunrise. I can't think of a reason that value wouldn't be there - is it a brand new or newly hard-reset hub?
You may just want to go into your app instance and click done. That should run through the process again.
I had to reset it recently due to corrupted database. I have done that but does not resolve the issue. It is weird, but I shall put this aside until my hub starts getting corrupted database on a daily basis since a few days ago.
