Susume Lv 1
My guess is there are very few known proteins with similar sequences. If the algorithm bases its prediction on proteins that are slightly similar but not really related, it can come up with wildly varying SS predictions.
I think this protein only exists inside the host cell - it is probably not packaged into the capsid when the virus exits the cell to travel to a new host. Instead, when outside the cell, it is carried as instructions in the RNA.