Polyhedra plugin creating unnecessary floating panel in R8

I installed Polyhedra on R8 and added its tab to the main toolbar. Now every time I start R8 a floating panel with the contents of that tab appears, even if I deleted it the previous time.

I don’t need the floating panel as I have the tab on the main toolbar: how can we stop it appearing?

(Rhino 8.2.23325.14001)

Thanks, I logged this as RH-78800 Toolbar Continuously Appears