Unhappy happy baby

My baby seems happy for short amounts of time. 15-20 min. And then fussy, then tired. She’s a short napper but also spits up a few times a day. Idk if this is from not napping good or if she’s having tummy issues. My husband said she’s always been like this so idk if it’s just who she is or what. Anyone else’s babies like this? I don’t remember going through this with my first 😭 and she’s not in a leap either