This is a problem I have on the iPad but not the iPhone so it is likely an Apple thing. Still it makes no sense to me. Here is the scenario.
Cache view and Open in geocaching.com. Transferred to Safari and find I am not signed in. Sign in. Switch to Cachly and open another cache in Safari -- presto not logged in for the new tab that is created. If I copy the URL to the previous tab that is signed in all is good. I did choose Remember Me when signing in so there ought to be a signed in cookie. This fails in Cachly and Geosphere so I figure it is Apple. Using a Geosphere bookmark for Open in Chrome, I never have the problem. Nor is it an issue when opening in UIWebView.
I just ran into it again when going to Cachly support forums. I have to sign in every time I use the link. Any ideas? It is very annoying. If there is no other fix, an open in Chrome setting would be a way around it.