Angela, you do have Windows 11, S mode only means you must download apps from the store app, and cannot download any app from outside of the store app. So it is not relevant here. You can always switch out of S mode for free
I am not sure what you meant by Microsoft 365 is a bundle and Windows is not. What I am trying to say is Windows 11 itself doesn't come with MS365. Unless it is a promotion offered to you by the computer's manufacturer, in your case, it is HP. This is why HP should be contacted for this issue, to understand better what is all included in your order.
This is similar to the case when you buy a car, it typically doesn't come with XM satellite radio subscription. But the car dealership might give you a year's subscription as a bundle deal or promotion. If you don't receive that subscription or if the promption is cut short, you contact the car dealership, not XM radio.