Can you try 

function onChange(control, oldValue, newValue, isLoading) {
	
	console.log('current.variables.mrvs_set_1: ' + g_form.getValue('mrvs_set_1'));
	console.log('current.variables.mrvs_set_1_json: ' + JSON.parse(JSON.stringify(g_form.getValue('mrvs_set_1'))));
	
}