Durango

Yes they most certainly could be related. if the purge solenoid is opening but the gas vapors aren't flowing it could create a vacuum leak causing the engine to run lean and rough running or excessive fumes causing it to run rich. The reason you cant fill up is because the tank is full of gas vapors forcing the fuel to backup into the neck and shutoff the pump. check your Evap canister vent line to make sure its not blocked with charcoal pellets from a bad charcoal canister (evap canister) here is the diagram.

check and replace purge solenoid