datefield with listener problem

Vaadin 6 / 7 / 8
1

I create one datefield with listener:

dtInicial.addValueChangeListener(event -> buscarCaixas());

but when I click to open and select one date in first time works, but after this, when I click to open he closes automatic and I can`t change my date

2

It should work multiple times. What is happening in buscarCaixas()?