Welcome, my name is XXXXX XXXXX I will do my best to help you with your issue
Do you burn candles?
Or have a lot of wood fires?
no to both
What type of heat do you have in the house?
gas furnace high efficiency
Well, there doesn't seem to be any of the normal sources for this type of issue which is usually caused by smoke collecting on the wall and ceiling surfaces. It shows up the outlines of the studs or ceiling joist or rafters because they are a different temperature than the surrounding insulated areas. That said you can prime this area with a shellac based stain blocking primer like Bin or Kilz. It must be the shellac based version. Then apply your top coat. This will block the stains from bleeding through. There is no way to tell when or if they will return
What you are telling me is that some form of dirt or soot is in the air and the difference in temp on the surface of the ceiling space is attracting it causing the ghosting
That is usually the cause when this type of "ghosting" shows up.
The uniformity of the pattern eliminates other likely causes
Thanks you just partially answered my next question but still what is say another potential cause?
I know of no other causes for this type of issue. That's not to say no other cause exists. I've seen exactly what you describe several times in person and have heard about many other similar cases.
Thanks for your help