const replaceNewlines = (line: string) => {
    const text = line.split(/\r?\n|\r/g);

    return (
        <>
            {
                text.map((part, index) => (
                    <React.Fragment key={index}>
                        {index > 0 && <br/>} {part}
                    </React.Fragment>
                ))
            }
        </>
    );
};

<BlocksRenderer content={children}
                blocks={{
                    paragraph: ({children}) => {
                        return (
                            React.Children.map(children, (child) => {
                                if (React.isValidElement(child)) {
                                    const {props = {text}, ...rest} = child as Child;

                                    /** @fix https://github.com/strapi/blocks-react-renderer/pull/42/files */
                                    if (typeof text === 'string') {
                                        return {
                                            ...rest,
                                            props: {
                                                ...child.props,
                                                text: replaceNewlines(text)
                                            }
                                        };
                                    }
                                }

                                return child;
                            })
                        )
                    }
/>