This appears to still be the case in 2026...

It does indeed look like the Listener is not passing the shouldCalculateReceiveTime through to the connection. I tried setting it manually within the listeners newConnectionHandler handler: listener?.newConnectionHandler = { connection in if let options = connection.parameters.defaultProtocolStack.internetProtocol as? NWProtocolIP.Options { options.shouldCalculateReceiveTime = true } ... But that doesn't work either...