I have the same issue - I’m on Series S and can’t download the Japan update either. I have done a clean install and deleted my save files as well, but this hasn’t done anything.
I also made a ticket and explained the issue to the support. I got an answer explaining how they are sorry for me not getting my premium version content altough I explicitly explained that I’m using the game pass standard version for now, and I made sure I explained my issue very clearly anyway.
The final ticket answer told me that I should receive an xbox live message with a redeem code to help me to download the missing content…
a) it seems like the support is an automated bot or they are very incompetent.
b) getting a xbox store redeem code doesn’t help with a download happening inside the game anyway.
So, I’m going to make a new ticket tomorrow and hope an actual human reads it because if not, the situation is impossible to solve.
I know I should use a PC for sims anyway because it’s just way more handy and gives you more options for everything (I had Prepar3d in the past etc) but for now I don’t have an access to a beefy desktop…