Try changing your voice settings, you'll find them in the "Voice Settings" tab. Each attempt to generate a voice will bring a different result (especially noticeable at low stability settings). The performance of the voice is also highly dependent on the voice itself; if you are using a pre-made or voice-designed voice, they tend to be more tempered and less emotional, while a cloned voice tends to exhibit a wider emotional range but that is also highly dependent on the original voice used for the clone.
