Discord.js 14 ping is returning -1

May someone explain me why when I run put this in my code in the ready event :

console.log(client.ws.ping)
console.log(typeof(client.ws.ping))

console.log(client.ws.ping)
console.log(typeof(client.ws.ping))

console.log(client.ws.ping)
console.log(typeof(client.ws.ping))

console.log(client.ws.ping)
console.log(typeof(client.ws.ping))

I get the following output:

 -1
number

 -1
number

 -1
number

 -1
number

Thanks