im having the same problem, more than 20 turns have passed, they havent canceled it yet, and yet in my trade screen is says that there is no active trade between my civ and theirs, only potential.
however there is still ROP going on between us because in the treaties section, it says there is a rop agreement between us, when i move to trade, it only says potential between us.
also, they are currently in my territory and i cant say "get out or declare war"
so the rop must be still active
thanks still want to know how to cancel thanks