Extjs on resize column width textfield Ui get destroyed

Question

Basically, the problem that I have is the following:

When I resize the column in my GridPanel the textbox UI near Name get destroyed: the line on the right disappear. It should instead resize according to the width. How could I fix it?

This is my code:

...
columns: {
    defaults: {
        flex: 1,
    },
    layout:'auto',
    items: [{
             text: Strings.sharedName,
             flex: 1,
             minWidth: Traccar.Style.columnWidthNormal,
             dataIndex: 'name',
             //style: 'text-align:right;!important',
             filter: 'string',
             defaults: {
                 margin: '-28 30 -5 50'
             },
             items: [{
                xtype: 'container',
                layout: {
                    type: 'vbox',
                    align: 'right'
                },
                flex: 2,
                items: [{
                    xtype: 'textfield',
                    id: 'nameFilter',
                    listeners: {
                        change: function(field, value) {
                            filterGrid('name', value);
                        }
                    }
                }]
            }]
        }
...

Here a reproducible example:

https://fiddle.sencha.com/#view/editor&fiddle/3a41