Connection and loading issues

I am using a Samsung Galaxy S4 GT-9505 running Android 4.2.2




When I go to the pc in the morning, I have to sign in.
The day before I chose "Stay signed in for 2 weeks", so it shouldn't be nessesary.


Often the phone can't connect unless I enable WiFi.
Annoying and a waste of power.


I mostly use the Messages function.
When I connect, it is working okay.
After a while it is just "loading..."


Very often when I refresh (F5), then I have to login again, and it is working again.
Very annoying.


Any help would be appreciated before I start looking for a more stable solution.


rgds
Jan

I experience exacly the same problems

So do I on my Samsung Galaxy S3 GT-I9300 running Android 4.1.2