WriterT failing

WriterTFailure.scala

import cats._
import cats.instances._
import cats.syntax._
import cats.data.Validated._

type ErrorOr[A] = Validated[String, A]

def logDivide(a: Int, b: Int) = WriterT[ErrorOr, String, Int](
    divide[ErrorOr](a,b) match {
      case Invalid(e) => Invalid("Division by zero\n")
      case Valid(n) => Valid((s"Divided $a by $b\n", n))
    }
)

def chain[A,B](fa: WriterT[ErrorOr, String, A], f : A => WriterT[ErrorOr, String, B]) : WriterT[ErrorOr, String, B] = {
  fa.run match {
    case Valid((l,a)) => {
      f(a).tell(l)
    }
    case Invalid(err) => // Oh dear, no log here...
      WriterT[ErrorOr, String, B](Invalid(err))// .tell(l)
  }
}

val r1 = logDivide(10,2)

chain(r1, a => logDivide(20, a))
res96: WriterT[ErrorOr, String, Int] = Writ
erT(
  Valid(
    (
      """Divided 20 by 5
Divided 10 by 2
""",
      4
    )
  )
)