The notarisation update you linked to has absolutely no bearing at all on your save files.
Please open Terminal, copy and paste the following command and hit Enter/Return:
find ~ -type d -name "*The Sims 4*" 2>/dev/null
After a little while it will return the results of the search. Please copy and paste them here.
I am having the same issue. I have 20 years of experience with this game across all 4 versions and never have had this problem before. When I open the game my saved households aren't there. It doesn't matter how many times I click save or save household to gallery, if I quit the game or it crashes, when I reopen it it's as though I've never played any households in Sims 4 before. I'm struggling a bit to follow along with the advice you gave as it seems me and OP have slightly different results from the 1st terminal search, but these are the results I see from the first terminal search you suggested:
rachaels-mbp:~ rachaelfox$ find ~ -type d -name "*The Sims 4*" 2>/dev/null
/Users/rachaelfox/Applications/The Sims 4 Packs
/Users/rachaelfox/Applications/The Sims 4.app
/Users/rachaelfox/Applications/The Sims 4.app/Contents/Resources/The Sims 4.app
/Users/rachaelfox/Documents/Electronic Arts/The Sims 4
rachaels-mbp:~ rachaelfox$
Any suggestions you have on how to fix this would be greatly appreciated! Thanks 🙂
