I've been having an issue after upgrading from a Nexus 4 to Nexus 5 where the phone will not re-connect to the home network (or will only reconnect to GSM with no data) after losing connection. This happens for example when going into an elevator or parking garage; I'll lose signal and when I get back into a signal area it won't reconnect unless I go to the "Mobile networks" -> "Network operators" menu and select "HOME" or "Automatic Registration". I'm using Straight Talk wireless with an older T-Mobile SIM (before they switched to only AT&T). I've called Straight Talk a few times to try and debug this, but the only instruction they've given me is to reset the APN and set it up again, which I've done a couple times to no avail. They claim that the SIM card is good on their end. Any ideas what might be causing this?