NullPointerException in KustoClientCache when reading from Kusto

Question

The following NPE is happening when attempting to read from Kusto. This is inside MSFT classes and the error message is non-informative. How can this be diagnosed?

2023-10-03 12:52:34,974 INFO - 23/10/03 12:56:50 ERROR kusto_reader:
 [corrId:4838f3b3-c495-461f-9353-8381e3e968e7] Exception raised in
    KustoReader.read.read. exception: An error occurred while calling o71.load.
: java.lang.NullPointerException
    at java.base/java.net.URI$Parser.parse(URI.java:3104)
    at java.base/java.net.URI.<init>(URI.java:600)
    at > com.microsoft.kusto.spark.utils.KustoClientCache$ClusterAndAuth
          .$anonfun$ingestUri$1(KustoClientCache.scala:79)
    at scala.Option.getOrElse(Option.scala:189)

The specific line 80 of the exception is shown below

KustoClientCache.scala

  private[kusto] case class ClusterAndAuth(engineUrl: String, authentication: KustoAuthentication, ingestionUri: Option[String], clusterAlias:String) {
    val engineUri: String = engineUrl
    val ingestUri: String = ingestionUri.getOrElse(new URIBuilder().setScheme("https")
      .setHost(KustoDataSourceUtils.IngestPrefix + new URI(engineUrl).getHost)
      .toString)   # NPE error happens on THIS line

Given the NullPointerException happens on a URI I was curious to see what that URI might represent. I was unable to determine: maybe it is an internal services hidden URL for a caching server?