I remember a similar issue when I was redoing my living room. Turned out, I had accidentally hidden a layer in my design software. Maybe it's something simple like that for you too?
One thing that helped me was checking all my layer settings and making sure nothing got hidden by mistake. Also, are the floors visible in the 3D view but missing in the plan view? That could give you a clue.
By the way, if you're ever thinking about adding more light to your space, you should check out these amazing sunrooms: https://www.scottsofthrapston.co.uk/sunrooms/. They might inspire you for your next project!
