Doc comment: how to document closure arguments of func argument?

Edit: Maybe a bug? [SR-14026] Doc comment for closure parameters of function parameter: work for top level func, but not nested member func · Issue #60696 · apple/swift · GitHub

In Xcode Version 12.3 (12C33), doc comment of closure parameters seems to be broken for nested func:

  1. In Xcode Playground, Option-click do not bring up the doc comment at all, so I try with a SwiftUI view...
  2. doc comment of closure parameters work only for top level func, the exact same doc comment is "No description" for nested func inside extension:

Option-click on definition works:

Option-click on call site do not:

import SwiftUI


/// Description
/// - Parameter closure: closure description
/// - Parameter first: first parameter
/// - Parameter second: second parameter
func docfoo<Element>(by closure: (_ first: Element, _ second: Element) -> Bool) {}

/// Description
/// - Parameters:
///   - closure: closure description
///   - first: first parameter
///   - second: second parameter
func moredocfoo<Element>(by closure: (_ first: Element, _ second: Element) -> Bool) {}

extension Array {
    /// Description
    /// - Parameter closure: closure description
    /// - Parameter first: first parameter
    /// - Parameter second: second parameter
    func docfoo<Element>(by closure: (_ first: Element, _ second: Element) -> Bool) {}
}

struct ContentView: View {

    func junk() {
        // works here
        docfoo(by: { (a: Int, b: Int) in a < b })
        // works here
        moredocfoo(by: { (a: Int, b: Int) in a < b })
        let a = [Int]()
        // do not work here (No description)
        a.docfoo(by: { (a: Int, b: Int) in a < b })
    }


    var body: some View {
        Text("Hello")
    }
}

Can someone kindly verify for me please. I thought it was my mistake in formatting....
:pray: