During a receipt application we created a claim investigation we are unable to create a chargeback

Good morning,

When a customer is doing a short payment, during receipt application we can create a chargeback by selecting an invoice and then clicking on the chargebacks button.

But we do not always know to which invoice a chargeback is related or it may be concerning various invoices. If so during receipt application we used to first create a claim investigation and then where able to click on the chargeback button to create a chargeback.

Now after creating the claim investigation the chargebacks button is greyed out.

Could someone suggest why this button is greyed out and how to resolve this?