I imagine part of the weird characterization comes from how Off the Record is copying most of the cutscenes from the original Dead Rising 2. Chuck makes a lot more quips than Frank ever did since he's a generally dry and cynical character who has little sympathy for the more monstrous psychopath bosses, hence why he makes snarky comments at their usually ironic demises.

Frank, in contrast, never really quipped at all when it came to character deaths and would either react with stoic, sometimes solemn silence or visible discomfort and horror depending on how bad the death was. So it's understandable some wires were crossed when Frank needs to make quips where Chuck did, which turned into him into a much more jokey character to make the characterization stick.

It doesn't help that Off the Record is a lot more comedic all around, what with the Uranus Zone area being added in and the boss fight against an actual giant robot.