No, the PC-1091R is not directional
AFAIK.
Did you check if your X0 RD is correctly set up? If the cage and pulleys are not aligned with the cog the chain drops to the lower one when you backpedal. Try turning the barrel adjuster and eighth or a quarter of a turn and see if it improves.
I'm using a KMC link on my PC-1091R. Haven't had a problem yet. I don't know about Wipperman though.