I’m in franchise mode and the game Stays in simulation mode

It sounds like your save might be corrupted. You could try deleting the personal saved data for NHL 26. However, there's always the risk your save could be deleted. It should download from the cloud, but I can't guarantee that. Try following these steps:

1. Highlight NHL 26 and hit the Menu button on your controller
2. Choose Manage game and add-ons
3. Go to Saved data
4. Select your gamertag and choose 'Delete from console'

After this, try playing again and let me know if it works or not.