Tuple encoder produces wrong results with Option inputs

import org.apache.spark.sql.{Encoders, Encoder} 

case class Required(name: String) 
case class Optional(name: String) 

implicit val enc: Encoder[(Required, Option[Optional])] = Encoders.tuple(Encoders.product[Required], Encoders.product[Option[Optional]]) 
 
spark.createDataFrame(Seq( 
(Required("1"), Some(Optional("1"))), 
(Required("2"), None) 
)).as[(Required, Option[Optional])].collect()

Array((Required(1),Some(Optional(1))), (Required(2),None))

Array((Required(1),Some(Optional(1))), (Required(2),null))