IOS react-native-webview session problem

Hello, i have a small problem with my managed expo app.

My app consists of a webview and a small navigation where user can register for a push service.
Im getting the push token via “getDevicePushTokenAsync” and send it to our server where it gets saved. The server saves the token with a session_id. On a webpage that is been called with the webview i can set settings for the push service wich are saved in connection to the session_id.
On Android everything works fine, but on IOS the session_id changes every time i open the app.
I send the token to the server via fetch and enabled the sharedcookies on the webview.

Would be nice if i could get a little help.