I think they struggled early on for different reasons.

American Dad was too laser focused on being a political satire show and I just don't think the writers were equipped to write a good political show. It just comes off as angry and with unlikable characters. Once it loosened up a little bit, having that political satire premise as a foundation gives the characters a baseline to work from and they all feel distinct because of it.

The Orville feels like Seth didn't want to make a comedy. It feels to me like he just wanted to make Star Trek, but because he's "a comedy guy" a lot of the humor, especially early on felt like it was put in to meet some expectation of Fox that a Seth show be a comedy.