Big AIs require better CPU power. You should try with a smaller one to see if it comes from it. Otherwise, you can adjust the options to reduce the CPU needed.
Keep the generation’s max length to ~40 Increase the max time to leave more time to the AI to generate text Greatly reduce the Context max length and the memory max length (This takes a lot of CPU when your story uses it) Also, uncheck the “Remove unfinished sentence” as it might delete the AI’s ouput if it doesn’t finish its sentence.