Lots Continuously Disappear/Revert to Default

[Rant: My game is now unplayable after spending about $2,000 on all of the expansion packs and kits. This is unacceptable. I have ZERO mods and ZERO custom content running, and I've installed every single pack and kit available. I've also run the repair tool multiple times. EA needs to stop putting the blame off on their customers and actually fix the product people are complaining about. These packs and updates should never be released before thorough testing. Any testing at all would have revealed these bugs immediately. If this continues, I will never buy another EA product again.]

The only lot that seems to remain as I made it is for the sim I'm actively playing. All other lots either revert back to the default, or they have blank lots. I've had weird llama icons blocking a portion of the map in Tartosa. Planet Honey Pop! disappeared and turned into a residential lot with a giant pit in it. Since I hated the building anyway, I rebuilt it and then it wouldn't properly create a floor even after flattening the lot (seems like there was leftover code from the platforms doing something funky). Then the sims wouldn't go into the building (for no obvious reason, and in a later load they were fine with it).

I had over 20 households in my previous game save and had to abandon it when all the houses I built for them (in every neighbourhood) disappeared. I spent months on that game save, and it was all for nothing.

I've been told it's got nothing to do with the Royalty & Legacy Pack, but that's been so buggy, I don't know what to believe. If it's the update, what did they update that would cause lots in every single neighbourhood to disappear?

When I opened a new game save and started fresh, I removed all default houses. [I wish the company would stop trying to make buildings, as the houses are awful/ugly and unusable anyway, with illogical floor plans (they're only made to look a certain way outside, which is the wrong way to design buildings).]

I am running this game on an ASUS Strix Scar 18 that cost five grand. It is one of the best gaming laptops out there. The fault does not lie with my PC. The fault lies with releasing packs and updates before they're ready. Fix the errors that are already there before chasing another cash-grabbing expansion pack. If you can't make the game work as it is, more pathways to error shouldn't be created. It's nonsensical to further complicate something that's already a tangled mess.