Looking at your example Material switch from here: https://mdbootstrap.com/docs/react/forms/switch/

I put in some console.log displays to check the status of the setting being toggled and I see that the onChange handler is being called twice

This is your code with just 2 lines of console.log inserted

this.state = {
        switch1: true,
        switch2: false
    };
}

handleSwitchChange = nr => () => {
    let switchNumber = `switch${nr}`;
    console.log('switch number is ', switchNumber)
    this.setState({
        [switchNumber]: !this.state[switchNumber]
    });
    console.log('switch', !this.state[switchNumber])
}

render() {
    return (
        <>
            <MDBSwitch checked={this.state.switch1} onChange={this.handleSwitchChange(1)} />
            <MDBSwitch checked={this.state.switch2} onChange={this.handleSwitchChange(2)} />
        </>
    );
}

}

the output displays like this when switch 1 is toggled.. The second switch is not being touched.