Cookies not showing up when first opening app. Only when refreshing the app.

When I first open the app, PHP does not receive cookies from previous sessions. However when I swipe down to refresh the page, PHP get the cookie information.

I am using cookies for login information, and this means it shows he is not logged in even though he is.

I did a test: set_cookie.php

I then closed the app, and reopened it, and ran this on the Home page:

When I load the app, the cookie isn't set. But when I swipe down to refresh the page, the cookie is now set.

I'm sure I've done something wrong, but what are your thoughts on how I cant debug this? Something to do with CloudFlare?