How long did you cook the chuck for? With something like chuck, the time needs to be long enough for the connective tissue to breakdown and provide some tenderness to what is a harder working muscle.
When cooking with sous vide one can think of the temperature as setting the 'doneness' of the meat and time controlling the texture. This is, of course, a simplification of the process, but it does help a little with planning.
With cuts of beef usually used for steaks, the muscle in question does a low amount of work and is naturally tender. Therefore we can cook for shorter times, from an hour up to four, and still get a tender piece of meat.
Harder working muscles, those often used for slow roasts or casseroles and braises, require slower cooking to break down the collagens to produce tender end results. These tend to be cheaper cuts and frequently much more flavourful than the steaks. With sous vide they can be cooked for a long time but still be kept at the medium rare stage due to the temperature control. That's where things get interesting. With the control sous vide offers you can have a super flavourful piece, like chuck or cheek or blade that can be served as a beautiful medium rare steak and cut with a bread and butter knife.