Just today this issue began. While building a settlement I noticed I could no longer place certain items under the power category. Each settlement had a different item I couldn't place too, which made it weirder. At Sanctuary it was all power pylons, at the Castle it was all conduits, and at starlight drive-in it was generators. And I know it isn't some cap on the number of items that can be placed because at Starlight Drive-In I had placed nothing at all there before this, but I still couldn't place any generators, and I have no massive settlement builds anywhere.
If anyone has had this issue, had it and fixed it, or has suggestions please let me know...