window.confirm() or confirm() throws an error when FDK pack/run

We have some custom logic that asks the Freshdesk agent if they want to create a ticket or not:

function promptTicketHandling(callData) {
  if (_requestTicketCreation == "Yes") {
    setTimeout(function () {
      if (confirm("Do you want to save the ticket")) {
        createTicket(callData);
      } else {
        console.log("Ticket will not be saved.");
      }
    }, 1000);
  } else {
    createTicket(callData);
  }
}

But now when I run fdk run i get the following error:

The local server could not be started due to the following issue(s):
✖ app\EmbeddableApp.js::319: Unexpected confirm.

We prefer not to use 

client.interface
		.trigger("showConfirm",

because it has proved quite buggy, especially when the agent waits a while before pressing confirm.

I have already tried replacing the method with window.confirm, but this unfortunately doesn't solve the error.

Has anybody faced this specific issue before? How did you solve it?