It could be one of two things; either the scandoubler/flickerfixer in the PIV is broken, or there is something wrong with the video port in the A2000.
One thing to try would be removing the PIV and cleaning the contacts on the video port edge connector, and blow any dust out of the port.
If there is an Amiga user group in your area (i know, not likely these days :-( ), someone may have another PIV you could swap out and see if the card is at fault.
