Extjs empty combo box value on expand click

Extjs empty combo box value on expand click

i have created lazy loading combo box, which queries data by entered
value. But i have issue when value is loaded from database and i click
expand list button, it sends request with empty mask instead of taking
value of combobox, it seems, that empty value is taken for some reason.
Here is my combo box :
editor : {
xtype : 'lazycombo',
minChars : 1,
pageSize : 20,
id : 'tax-code-combo',
store : 'TaxCodesStore',
triggerAction : 'all'
}
and here is request params :
limit 20
mask
organizationId 108
start 0
mask is empty instead of before set value.
Thanks for help