I have this issue on I believe two of my mods but the issue for me at least is due to when they use the cheat giveitem "Blueprint ect… However, when they craft it works. So I do know one issue is definitely the cheat command but from what I was told the only other option is to put items in the master list and spawning using the item ID but then you run the risk of your mod not stacking with other mods. I have not tested whether adding to the master list but not telling players the item ID would fix the cheat giveitem command. In other words, I don’t use the master list and when they use the cheat giveitem blueprint they have issues, and not only with structures but even weapons and ammo that might be in the mod. It only seems to work if they spawn, then save game, leave game, and then return, which then the items work. But I wonder if I still use the master list and then they use the cheat giveitem blueprint would that fix the issue. Of course, this is the issue I have but perhaps you can test as well and see if it fixes your problem.