Implicit resolution fail in reflection with ToolBox

I am trying to generate Avro4s's RecordFormat in reflection based on class path. The following code throws an error.

case class MyCaseClass(a: Int)
println(toolBox.compile {
  toolBox.parse(
    s"""
       |import com.sksamuel.avro4s._
       |import mypackage.MyCaseClass
       |RecordFormat[MyCaseClass]
       |""".stripMargin
  )
}())

could not find implicit value for evidence parameter of type com.sksamuel.avro4s.Decoder[mypackage.MyCaseClass]

RecordFormat is like

object RecordFormat {
   def apply[T <: Product : Encoder : Decoder : SchemaFor]: RecordFormat[T] = apply(AvroSchema[T])
}

I can see, it can resolve Encoder[MyCaseClass] and SchemaFor[MyCaseClass] but fails for Decoder[MyCaseClass].

The same code can resolve RecordFormat[MyCaseClass] without reflection.

I can see that Decoder is implemented with macro similar to Encoder.

implicit def applyMacro[T <: Product]: Decoder[T] = macro applyMacroImpl[T]

Why reflection cannot resolve the implicit evidence?