The Weight and Balance Set from OFP does not completely work. If you import a simbrief plan it brings everything in (passengers, cargo and fuel). BUT, in the Aircraft weight and balance it won’t set the proper payload and cargo weight. The fuel amount is correct.
The plane will be loaded, it just doesn’t reflect in the toolbar window.
I believe this is a known and logged bug.
You will generally see this behavior on all planes that support payload management via the EFB etc.