Focus on input does not always call keyboard for ios angular

Question

I am using angular 1 and md-autocomplete

      <md-autocomplete
            md-autofocus="true"
            md-autoselect="true"
            md-select-on-match="false"
            md-search-text-change="$ctrl.searchTextChange($ctrl.searchText)"
            md-search-text="$ctrl.searchText"
            md-items="item in $ctrl.performQuery($ctrl.searchText)"
            md-item-text="item.name"
            md-no-cache="true"
            md-min-length="0"
            placeholder="{{'core.common.filter.results' | translate}}"
            md-selected-item-change="$ctrl.onItemChange()"
            ng-readonly="$ctrl.isReadOnly">

Here how my autocomplete is defined

        setFocus(){
             setTimeout(() => {
                 this.$element.find('md-autocomplete').find('input').focus()
        },0)
    }

From another method I call setFocus() func

for desktop and android everything works correctly. Both necessary functionality are called: autocomplete selectors and keyboard(for mobile)

I also debugged and found that correct input is focused

but the problem is that focus on input does not call keyboard on ios every time, it can happen randomly. in this time autocomplete suggestions are shown every time

also tried to use querySelectorAll and querySelector the same problem

document.querySelectorAll('md-autocomplete > md-autocomplete-wrap > input')[0].focus()