SharedArrayBuffer is not defined

Hey
I'm trying to convert Blob data from RecordRTC from webm to mp4. The script seems to be working and initialized, but React/NextJS throws a SharedArrayBuffer. Searching for that term gives me some answers about some vulnerability in SAB, but I don't understand what's up and down. It says there's a way to re-enable it though?
Is it a bug in ffmpegwasm or is there something deeper to it? As I'm creating a ReactJS website, I should be able to follow your example of your 'react-app' no?

Thanks