Gas grill propane leak...

Ok, I have a ducane gas grill and enjoy grilling year round. I live in Upstate NY and was grilling in below freezing temps when I ran out of propane. I connected the new tank and heard leaking so I shut off the valve. I tested connection and there was a leak where the plastic connector screws on the tank. No worries I bought a new benzomatic regulator hose and thought I’m back in business, except the brand new hose is leaking in the exact same spot. Is this sheer coincidence, or more of an issue with below freezing temps causing contraction where there would normally be a flush connection? I can always buy another hose but thought I’d pose the question. Thanks.

I suspect the valve/connection on the tank is compromised in some way. If you can return or exchange the tank.