Greetings Exile,
Thank you for reaching out to us. Could you share some additional information?
Do you have your game installed on an SSD or HDD?
Is the console stable while playing other demanding games?
In the meantime, here are some steps that might help you. Please ensure that your save is stored on the Xbox cloud before trying each of the following:
Reset the console cache by holding the power button for about 10 seconds until the console powers off, then disconnect it from the power outlet for a couple of minutes, then try loading it into your SP session.
Try to perform a soft factory reset while keeping games and apps.
We await your reply.