Question, did you activate it just recently? I know it used to be unlocked and was planning on getting one for an upcoming overseas trip but reviews on Best Buy and reports on SlickDeals say Apple/VZW have started locking these handsets.
Have you tried it with AT&T or T-Mobile SIM?
Yeah, I've had it about a week and have confirmed it to be unlocked.
From my understanding, the only difference between the Verizon Prepaid SE and the standard Verizon SE is that the IMEI is pre-registered with the prepaid service. This, initially, makes them entirely locked to the service, and will hotline the phone if it's not activated first - IE, anything you do on it redirects to a call to the VZW hotline/*611.
For clarification, you can check out the rule from Verizon itself - ID: OST100112
You could also go directly to a Verizon store, and have them confirm the device is active for Postpaid and is unlocked while you're there, which is exactly what I did. If needed, reference the rule above, and make them look it up, as it's the guideline they're legally required to follow due to regulations.
Hopefully that helps!