@hekatoraOh its worse for me now. It happens 100% of the time and rebooting doesn't help either. It does work if I start another game, quit that, then start Sims, it will load up no problem so now everytime I want to play the Sims , I boot up another game first. It's bizarre. Sims 4 is the only game this happens with ( hubby and I play lots of games) and no, it's not the memory space because this happened on my brand new Xbox series S with this being the only game installed at the time. I am suspecting this isn't just a generic xbox issue but some issue with the game and xbox working together.
And quick note: when playing the Sims and it says to restart for new "delivery" it never boots back up. All the time. I have to do the same thing I mentioned earlier. It's so annoying.