setCapabilityValue updates Homey, but not the Dimmer

Developers
1

What am I doing wrong if the this.setCapabilityValue call updates the values here https://developer.athom.com/tools/devices, but are not registered by the physical device (Fibaro Walli Dimmer)?

Changing the dim value in the webapp does update the physical device.

class FibaroWalliDimmerDevice extends ZwaveDevice {

async onMeshInit() {

    // Enable debugging.
    this.enableDebug();

    // Print the node's info to the console.
    this.printNode();

    this.registerCapability('onoff', 'SWITCH_MULTILEVEL');
    this.registerCapability('dim', 'SWITCH_MULTILEVEL');


    this.registerCapabilityListener('onoff', async value => {
        try {
            await this.setCapabilityValue('dim', value ? 1 : 0);
            return Promise.resolve();
        } catch (err) {
            return Promise.reject(err);
        }
    });

}

}

Sidenote: this.registerCapability('onoff', 'SWITCH_MULTILEVEL'); does not work either. The onoff-button in my Fibaro application does not work. It does read the value correctly, but it does not write.

2

This works as expected.

        this.registerCapabilityListener('onoff', async value => {
            try {
                await this.node.CommandClass.COMMAND_CLASS_SWITCH_MULTILEVEL.SWITCH_MULTILEVEL_SET({"type":"Buffer","data":[value ? 99 : 0,255]})
                return Promise.resolve();
            } catch (err) {
                return Promise.reject(err);
            }
        });