The ComboBox view of List widget can only display the initial value ?

Hi ,

I found the  comboBox view of List widget can only display the data for the 1st time ,  the bounded service return different data for the 2nd time then the list display empty.  

The dropdown view doesn't has the problem , but it requires panel so is not responsive .   

Is it a known issue ? 

Thingworx 8.4.2. 

Regards,

Sean