Re: Sims 4 using 6GB RAM out of 8 since update
@Kitukunn Try testing in a clean user folder: Move the entire Sims 4 folder out of Documents > Electronic Arts and onto your desktop, and when you launch the game, a clean folder will spawn with no content. (Your saves and other content will be intact in the folder you moved but temporarily not read by the game.) Don't add anything to the new folder yet; just start a new save and let me know how much RAM it uses.
If memory use is still high, quit the game, restart your computer, and this time, put the EA App in offline mode before launching Sims 4. Let me know whether this makes any difference at all.
I believe this is the case from your original post, but please also confirm that Sims 4 itself, as in, TS4_x64.exe, is using 5-6 GB RAM, rather than your system overall using that much.