Why navigating to protocol var definition doesn't work ?

Hello Xcode users,

I'm stuck with a weird editor behavior.

For example let's have those two files in a macOS Cocoa app :

Protocols.swift

//
//  Protocols.swift
//  testprotocoldefinition
//

import Foundation

protocol Test {
    var isSetVar:Bool {get}
    func isSetFunc() -> Bool
}

Implementations.swift

//
//  Implementations.swift
//  testprotocoldefinition
//

import Foundation

class Implementation : Test {
    var isSetVar: Bool = true
    
    func isSetFunc() -> Bool {
        return true
    }
}

When I do Navigate > Jump to Definition, or ctrl + cmd + click, or ctrl + cmd + J :

- on Test.isSetFunc, Xcode opens a popover where you can navigate to Test.isSetFunc or Implementation.isSetFunc, as expected

- on Test.isSetVar, nothing happens

- on Implementation.isSetFunc, Xcode navigate to Test.isSetFunc, as expected

- on Implementation.isSetVar, nothing happens.

Odd thing is when I try to Refactor > Rename... on Test.isSetVar,

Implementation.isSetVar is also selected to be refactored.

That means indexer does the job as expected.

Is it a known issue all developers can reproduce ?

How do you figure out to navigate from protocol vars to their implementations in the editor ?

I'm using Xcode 10.1 on macOS 10.14

I was experiencing this in Xcode 10.0 too

Thank you for your help

Kind regards

Maxime