No Cookies with Rails API, CORS and Next getInitialProps - ruby-on-rails

Question

I have a Rails API only backend with rack-cors installed at port 3000.
My NextJS is running on port 5000.
My goal is to consume a cookie set by the server within my NextJS app. It contains a JWT token which holds an email and roles, which will be decoded and used for Authorization.
With Postman I can see the Cookie.
I have set my Cookie in Rails with httpOnly, but I can't see it my Chrome-dev-tools.
When I set a httpOnly cookie with NextJS, it's present.
I can see it in the DevTools "response" when POST to Rails's /login but not in the Application -> Storage -> Cookies(see images attached).
It seems Chrome does not set the cookie in DevTools "storage", it's always empty. Equally if I use "httpOnly" or not.
Can someone help me to consume the Cookie on NextJS (client side)?
Rails.application.config.middleware.insert_before 0, Rack::Cors do
allow do
origins 'localhost:5000', '127.0.0.1:5000'
resource '*',
headers: :any,
methods: [:get, :post, :put, :patch, :delete, :options, :head],
expose: ['Per-Page', 'Total', 'Link', 'ETag', 'Set-Cookie']
end
Here I set my cookie in the Rails controller:
response.set_cookie(
"withIP",
{
value: auth_token[:token],
expires: 30.minutes.from_now,
path: "/",
domain: "localhost:5000", # tried to remove domain completly also tried "127.0.0.1" as domain, as well as '.localhost'
secure: Rails.env.production?,
httponly: true # Rails.env.production?
}
)
This is my request in the NextJS app:
return fetch(`${PublicApiUrl}/auth/login.json?${qs.stringify(options)}`,
{ method: 'POST',
headers: {
Accept: 'application/json',
'Content-Type': 'application/json',
},
credentials: 'same-origin', // also tried 'credentials' and with 'inline', as well completely removed at all.
})
.then((response) => {
console.log("RESPONSE", response); // 1* see image below
console.log("RESPONSE HEADERS", response.headers); // *2 ALWAYS undefined
console.log("RESPONSE forEeach", response.headers.forEach(console.log)); // ALWAYS undefined
console.log("response.headers.get('set-cookie')", response.headers.get('set-cookie')); // NULL
console.log("document.cookie", document.cookie); // nope
return response.json()
} )
.then((data)=>{
console.log("DATA", data); // returns my authToken
return data;
})
*1 console.log from above
RESPONSE
Response {type: 'cors', url: 'http://localhost:3000/auth/login.json?email=xxxxxxx&password=xxxxxx', redirected: false, status: 200, ok: true, …}
body: (...)
bodyUsed: true
headers: Headers
[[Prototype]]: Headers
ok: true
redirected: false
status: 200
statusText: "OK"
type: "cors"
url: "http://localhost:3000/auth/login.json?email=XXXXXX&password=XXXXXX"
*2 RESPONSE HEADERS (console.log from above)
RESPONSE HEADERS Headers {}[[Prototype]]: Headers