Unexpected route

ionic-v1
1

Hi there,
I have a routing problem I’m not able to solve.
In a view I have a button defined as follow:

<button class="button button-positive" 
  ng-click='newDemoLicense({{customerId}})'>
Add demo licence </button>

When I press the button the function in the controller is fired:

	$scope.newDemoLicense = function(customerId){
	console.log('new demo license id:'+ customerId);
	$state.go('tab.license.demo', 
		{
			'customerId': 	customerId,
			'licenseId':	null
		});
};

The states are defined as:

...    
.state('tab.license', {
url: '/license/:customerId/:licenseId',
views: {
  'tab-customers': {
    templateUrl: 'templates/tab-license.html',
    controller: 'LicenseCtrl'
  }
}
})

.state('tab.license.demo', {
url: '/licensedemo/:customerId',
views: {
  'tab-customers': {
    templateUrl: 'templates/tab-license-alt.html',
    controller: 'DemoLicenseCtrl'
  }
}
})
...

but with my surprise the page is redirected toward the URL:
http://localhost:8080/#/tab/license/1001//licensedemo/1001
(… I was in http://localhost:8080/#/tab/license/1001)
The page I see is tab-license.html and the recalled controller is the LicenseCtrl.
Seems the control is switched into the tab.license state: I guess it is caused by the #/tab/license in front to the required new URL.
Why the second URL was added to the previous URL?

Thanks!