I can reproduce the problem like this:
- install the Esri Geoportal Server on Windows using IIS
- install the Esri Resource Proxy on the same machine
- log in to the Geoportal (eg http://localhost:8080/geoportal/catalog/identity/login.page)
- in a new tab in the same browser, send a query to the Geoportal REST API via the Esri proxy (eg http://localhost/PHP/proxy.php?http://localhost:8080/geoportal/rest/find/document?f=pjson)
- switch back to the Geoportal tab, refresh the page, and note that the user is now logged out
This error does not occur for me using the sandbox Geoportal at http://gptogc.esri.com/geoportal/catalog/main/home.page (you can test it with this query)
Does anyone know why this is occurring? Is the problem occurring because the proxy is on the same machine as the Geoportal Server? Are there any known workarounds?
I don't know enough about how the login session works in the Geoportal Server, or what the Esri Resource Proxy is doing, to know how to debug this.