Can't submit build for external testing

In view "What to Test" after successful pick of build and valid description click on button "Submit for Review" appears message "There was an error processing your request. Please try again later."

In console i can see error "Failed to load resource: the server responded with a status of 422 ()" and additional information in url https://appstoreconnect.apple.com/iris/v1/betaAppReviewSubmissions:

{
  "errors" : [ {
    "id" : "004bb5b7-1761-4450-aa0a-43d8cc5d1a9a",
    "status" : "400",
    "code" : "PARAMETER_ERROR.REQUIRED",
    "title" : "A required parameter was not provided",
    "detail" : "The parameter 'filter[build]' is required but was not provided",
    "source" : {
      "parameter" : "filter[build]"
    }
  } ]
}

Tested on Safari and Chrome with cache clean and relogin.

Other build provides same error.