This is normal.
The values mentioned (and modifiable) in the bi-facial tool are intended to analyze your Bi-facial system in diverse conditions. This is a pedagogic tool.
If you have specified a 3D scene (with sheds or trackers), the simulation will take the parameters corresponding at best to these definitions in the 3D construction.
This is mentioned on the dialog:
Bifacial_Info.PNG [ 4.85 KiB | Viewed 2029 times ]
The only parameter which is really defined here and not specified in the 3D scene is the "Height above the Ground