Can't change App Availability due to backend error

I am trying to add new country to the list of countries where my app is available. App is already reviewed and released in 1 country.

I choose country, press Confirm and see this error: "Your app availability changes could not be saved. Try again later."

In DevTools I see this payload:

{
  "errors" : [ {
    "id" : "723157ee-6bde-44ef-a80b-1330c1e80d3c",
    "status" : "409",
    "code" : "ENTITY_ERROR.PREORDER_ALREADY_LIVE",
    "title" : "There is a problem with the request entity",
    "detail" : "A pre-order is already live for this entity.",
    "source" : {
      "pointer" : "/data/relationships/territoryAvailabilities/data/0/id"
    }
  } ]
}

I don't have any active Pre-orders, I am not trying to set up Pre-order, I want to make the app available now.

Can I somehow fix this problem myself? How can report it to Apple devs?