Iteration in LWC not working for 2nd element of input array

Question

I am working in LWC requirements where I have a list of records using this list I need to create inputs text. Once I loop through the list in LWC 'HTML component' my input texts are coming as aspected but while I enter the value in the text box the same value is updated to the 2nd element of the array. Below is my code.

 <template for:each={selectedCons} for:item="oli" for:index="index"> 
     <template for:each={olilist} for:item="oli2" for:index="ids"> 
        <tr key={oli.index}>
           <td>{index}</td> 
           <td>
               <lightning-input name='oliUnitPrice' access-key={index} type='Currency' id={index}  onchange={changeHandler} value={oli2.UnitPrice}>
              </lightning-input>
           </td>
           <td>
           <lightning-input name='oliQuantity' access-key={index} type='Number' id={index}  onchange={changeHandler} value={oli2.Quantity}>
           </lightning-input>
           </td>
           <td> 
           </td>
       </tr>
   </template>

If I enter 7 the 2nd rows also gets updated with 7.

My Js Code below.

@track selectedCons; 
@track olilist = [
    {                      
        Name: '',
        ProductCode: '',
        UnitPrice: '',
        Quantity: '',
        Product2Id : ''
    }
];  

showContacts() {
    this.bShowModal = true;

    this.selectedCons = [];

    let selectedRows = this.template.querySelectorAll('lightning-input'); 

    // based on selected row getting values of the contact
    for(let i = 0; i < selectedRows.length; i++) {
        if(selectedRows[i].checked && selectedRows[i].type === 'checkbox') {
            this.selectedCons.push({
                Name: selectedRows[i].value,
                Id: selectedRows[i].dataset.id,
                ProductCode : selectedRows[i].value,
                Product2Id : selectedRows[i].value,
                UnitPrice : selectedRows[i].value
            })
        }
    }

}

 changeHandler(event){       
    // alert(event.target.id.split('-'));
    console.log('Access key2:'+event.target.accessKey);
    console.log('id:'+event.target.id);
    console.log('value:'+event.target.value);
    console.log('name :'+event.target.name);       
    if(event.target.name==='oliUnitPrice'){
        this.olilist[event.target.accessKey].UnitPrice = event.target.value;
        console.log('name 2 :'+event.target.name);  
    }

    else if(event.target.name==='oliQuantity'){
        this.olilist[event.target.accessKey].Quantity = event.target.value;
        console.log('name 2 :'+event.target.name); 
    } 
    console.log("Olilist"+JSON.stringify(this.olilist));
 }

'selectedCons' is working properly. I am accessing it with 'accesskey'. Once deleting the 2nd rows element, getting below error.

Please help me in this!