No shortcuts will be affected by changing the location of Documents in Windows..
@BabyForPree It sounds like a symbolic link is the best option for your current setup. They're quite reliable, as long as you're careful with the syntax, and not all that complicated to make.
As for why this happened in the first place, what was your original setup? There's no way that Sims 4 would have automatically read your user data if it was outside of your Documents directory, which makes me think perhaps you had a symlink set up in the first place and it was recently deleted. As to how or why that happened, I can only speculate, but OneDrive is often the culprit when unwanted changes are made to the contents of Documents.
What other issues are you seeing right now, aside from your user data not being read?
@BabyForPree Sims 4 doesn't ask where you want user data stored, nor does the game launcher you use to install it. The game is programmed to always look in Documents > Electronic Arts. So no, reinstalling won't help.
I don't know what to tell you except that you must have done something specific to direct the game to your folder on D. Without being able to look at your system myself, it would be silly to speculate; I only know that this is not and has never been the default behavior.
