Not a bug, when its night, its dark as there are usually not any source of light. It’s annoying but it is how it is. You can always use flare you have in your inv when you spawns.

What I do not understand, why do the PC players only have Permanent Bright Light in the game ???

And we as PS4 players do not get that, sad?

I don’t understand what you mean. On public DayZ servers there is always a day/night cycle. Around 3 hours its day, and for around 1 hour its night.

Maybe you are playing on some custom private servers where they turned it off. These are not yet on the PS4.