Odd face "F" key results


In the first pic you see I have 2 edges selected. When I hit the “F” key to make a face, I get the result in pic 2. What do I have wrong?
I get similar odd results when I select 3 or 4 verts and try to make a face.
I’ve done a lot of designing in Blender and have never see this.
Thanks

To fix this I deleted the inner cylinder and made a new one.