But behavior alone cannot be an indicator for sentience as you can simply record behavior and play it back. Sentience has more to do with sensory perception and

But behavior alone cannot be an indicator for sentience as you can simply record behavior and play it back. Sentience has more to do with sensory perception and feedback loops than mental capability or intelligence. If a future AI attains sentience on a commodity processor, that wouldn't imply that the program is what achieved sentience, rather the computer running the program and all computers before had sentience and the AI is just an interface between the computer and humans that lets it express its sentience in a way that can be understood by humans. If you really believed that behavior is what drives sentience, then non verbal people with autism would have very low sentience and if they somehow overcome their non verbalism, they would gain sentience throughout their life, which is at odds with the fact that many people believe that animals in factory farms are sentient for instance, despite their poor language skills and complete lack of effort needed to achieve sentience.