no all orthodox do not reject the authority of the pope, this is an error, what they reject if they do is the idea that the Pope is somehow able to singlehandedly tell the church to overturn tradition.
I am not here to get you to understand eastern law since the concept of our law apparently has to be explained to an eastern catholic by a sedevacantist who is according to canonical norms excommunicated by his own church for violating canons. the irony is very funny