Ok. I don't think it's a bug. I believe there's a misunderstanding to how Sim Settlements work. I'll try to explain some of it.
Needs
Basic game: Every settler (leute) need 1 food (essen) and 1 water (wasser). They also need 1 bed (betten). (Extra: sheltered beds, beds with roof over them, gives better happiness (moral) values.)
Sim Settlements: every settler still need the same things, but now we also have plots that have needs. Every plot need power (except farm plots). Some more power, some less. But plots can also need food and water. As the building grows a level, the plot need often change. This is called dynamic needs.
Example:
At level 1, the plot need 1 power (energie)
At level 2, the plot need 2 power and 2 water
At level 3, the plot need 2 power, 3 water and 3 food.
If you look at the plots information sign (plakette?), you will see how much the plot need.
HUDmeters
The values in the HUDmeters are not the same values as in the workshop mode status bar. The workshop mode values are what the settlement actually produces. The HUDmeters show how well you meet the needs of your settlement in %.
Basically you have: production / needs = HUDmeter.
The 3 top ones (food, water, defence) are most important - if they aren't at 100% you will lose happiness (moral).
Happiness
good for happiness: enough food, water & defence + doctors, some martial plots, all recreational plots, the toy factory.
bad for happiness: too little food, water & defence + almost all industrial plots. Every robot living in your settlement.
Solution(s)
Produce more food and water - or - shut off dynamic needs (this will stop plots from needing more and more as they level up).
