So, in case anyone else faces this issue I'll detail my workaround.
Evicting the household, saving the lot and bulldozing the house before replacing the lot and moving the household back in didn't work at all. The save file itself seems to be the whole issue. A new save on a new game had no issues at all.
So my workaround was:
The basic idea is to save your lot in build mode and then save your household in edit Cas. Then start a new game with a new save, find your lot, evict whoever lives there (if someone lives there), bulldoze the lot if another house is there and put down your house and move in your house hold (I used a very large lot so I had to do both of these). You won't be able to keep any of your money so if your house is expensive (and it probably will be moving all of your stuff with it) you'll have to move your household onto a cheaper lot, use the money cheats to get your cash back and then move into your house.
This didn't work exactly like that for me. I have NPCs in my world I wanted to take with me that wouldn't transfer over and collectibles in storage that wouldn't transfer over. To get around the collectibles issue I just took everything out of storage and threw it on the floor so it would be saved with the lot. This was the only way to get all of my perfect quality plantables to the new save.
As far as the NPCs I had to invite them to my lot and then add them to my family before saving the household. This was a pain in the * since my clock was stuck at 2:02am when all other NPCs are sleeping and won't visit the lot. But I found out I could move the clock forward if I saved before 43 game minutes had passed. So I kept inching the clock forward 40 game minutes at a time, saving, ending the game and reloading for another 40 game minutes so on and so forth until it was 6:30am game time and I could invite the NPCs over.
Also, I'm doing an alphabetical 26 generation challenge wherein the first generation's names start with A, the second B, the third C so on and so forth. I set up a basement crypt where I keep paintings of each generation along with their urns. Moving the lot into the new save renders your urns useless which really breaks the immersion for me as I was on generation E. I like to go down there and look at my progress and read the epitaphs. To get around this (and this isn't really a cheat as it is more of a work intensive trick) in the new save I kept inviting new NPCs to the lot, renaming them after each family member's urn I needed to replace and then killing them for their urn. Then I rewrote the epitaphs and replaced the non functional urns with the new ones. I may know it's not the real urn, but for all intents and purposes I have interactable urns with the correct names and epitaphs again. Except for losing creation credit on all paintings (the paintings themselves transfered over) everything seems to be the exact same and working on the new save. I lost all the repair parts I'd saved and all the fruits and veggies I kept in the fridge but only because I didn't want to throw down 50 or so objects per item when I could regrow and replace them over time.
This took a lot of time and effort and I'm really irritated that 1700 hours into the game I have to do this because an update screwed the game up (it worked perfectly fine before the update yesterday) but at least I can still continue with this family on this challenge instead of having to start all over.
