Right, I had done that, and it was not working with any of the dozens of different settings I've found online for this phone. I was concerned that having the other entry for the default Verizon APN may be causing the issue.
I have another android phone which is working on ST, but it's a Google Nexus 5. I even tried to use the same settings from that known working setup, with no luck. The Nexus is mine, and the S4 is the girlfriend's phone. I'd convinced her that ST was much better, cheaper, and easier...which is proving to be wrong on the easier part of that. Should i be deleting the Verizon APN, if possible, once the card is inserted for Verizon? Would that be an issue to have it as an additional entry? I was also curious to find out what Samantha Timmons is using for the APN settings, if they were different from what else is posted here.