Why is scala.meta.Term.Param#toString dropping modifiers?

Question

I'm trying to rename the parameter of an anonymous function using a semantic scalafix plugin. The relevant code looks like this:

  case Term.Apply(func, args) =>
    args.collect { case Term.Block(List(Term.Function(List(arg), _))) =>
      Patch.replaceTree(arg, arg.copy(name = Term.Name("components")).toString())

The problem is, this is changing { implicit foo => to { components => (i.e. it's dropping the implicit modifier). I initially thought it was being dropped by the copy method for some reason, but I added some printlns and that's not the case: the implicit modifier exists on the copy, but just isn't being included in the toString output. Anyone know what's going on here? And how I can get the implicit to be included in the output?

printlns:

      println("***********ORIGINAL***********")
      println("toString:\t" + arg.toString())
      println("name:\t\t" + arg.name)
      println("modifiers:\t" + arg.mods)
      println("syntax:\t\t" + arg.syntax)
      println("structure:\t" + arg.structure)
      println("***********COPY***********")
      val copy = arg.copy(name = Term.Name("components"))
      println("toString:\t" + copy.toString())
      println("name:\t\t" + copy.name)
      println("modifiers:\t" + copy.mods)
      println("syntax:\t\t" + copy.syntax)
      println("structure:\t" + copy.structure)

output:

***********ORIGINAL***********
toString:   implicit app
name:       app
modifiers:  List(implicit)
syntax:     implicit app
structure:  Term.Param(List(Mod.Implicit), Term.Name("app"), None, None)
***********COPY***********
toString:   components
name:       components
modifiers:  List(implicit)
syntax:     components
structure:  Term.Param(List(Mod.Implicit), Term.Name("components"), None, None)

(notice that the copy has implicit in its list of modifiers, but it doesn't show up in the outputs of toString or syntax)