I did use Migration Assistant, but that was to transfer my stuff from a much older laptop (so not the MacMini M1) which I had never used when building the Horse Ranch house.
I uploaded my video showing the bug occurring to YouTube and I added a description to it explaining what is happening during the video. Here is the link: https://youtu.be/gyLHiQVC4EA
When I had tried to delete the platform while the bug was happening, the game didn't let me delete it (the video shows me doing this) and I attempted to draw a room after doing this in the same video and the room did not appear. If I were to try to save and quit my game the game would keep saving forever, so this is why I always force quit my game now as soon as the bug starts happening. Once I reopened the game and returned to build mode, the platform was gone because I had not saved my game before placing the platform, and I was able to place trees and anything else like normal, but every time I attempt to build a room, place a platform, place stairs, change a wall height or something similar there is a really good chance (not 100% chance) that the bug will be triggered again, so I've basically been saving my game every time I attempt to do something like this to not risk losing the progress I made.
I tried repairing my game to see if that fixed it before I ever reported the bug on this website, and unfortunately this did not work. But I suppose it doesn't hurt to try doing this again.
What you are describing here is exactly what I did when you told me to to see if the issue still happened with a clean Sims 4 folder. When I did this I was still having the same problem.
