I've tried just about everything and every combination possible, including reverting back to older saves, but the glitch pops up anyway after a couple of hours of gameplay, so I'm guessing I had better start a new playthrough and without the bUseCombinedObjects=0 edit to start with so it doesn't end up corrupting my game :/ That article by Arthmoor does shed some light on what's happening with the combined objects and why it's probably a bad idea to edit that in the first place... sigh. I feel sorry for all these awesome modders that put so much effort into making our games so enjoyable and have so many sticks put in their wheels, it just makes me appreciate the effort they put into making mods much much more. @Vormina For me the glitch started way before the Vault Tec dlc, I had updated some mods just before the glitch started so I thought maybe one of them was the culprit. I've never had problems with load orders using LOOT in Skyrim, FNV and FO3, I usually do read the mod authors page though to see if the mod has to be placed at a certain point in the load order but I find LOOT helpful as a starting point when sorting mods. Oh well, off I go to start another settlement building binge and see if everything goes smoothly this time. Thank you all for your input in this topic and I hope it can help others with the same visual glitch.