I’m not bilingual but I made friends with a guy who introduced himself to me as a stutterer. I was surprised because I never heard him stutter once. He said in his native language (an Indian subcontinent language spoken by a fairly small population), he had a terrible stutter, but they came to the US when he was in elementary school, he learned English at that time and never stutters in English. He said still when talking to his family in their first language his stutter is severe. I’ve never heard of anyone else with that kind of experience.