I have exact same problem.
I called Sprint to unlock my Galaxy S7 edge - which they did in couple of days.
The Settings> System updates> UICC Unlock was saying: "Your device is unlocked for any SIMs"
But when I tried to insert other carrier's SIM - the phone said: "Invalid SIM"
And now the Settings> System updates> UICC Unlock was saying: "Your device is locked to Sprint SIMs only" and it goes to "Hands Free Activation" and retries itself 5 times but no result.
My Phone Number has been already ported to new carrier but I can't figure out how to make my phone to work. Please advise.
Sorry to hear you are having issues with your Galaxy S7 Edge unlock process. I will be sending you a private message to get some additional information from you.
I am forwarding your information on to one of our telephone specialists and I expect to have a response soon. I will let you know what I find out.
@AmitRangara, I wanted to push another message out to you, to ensure you received it. Are you receiving an error about your SIM?
Hey mrlalamusa - were you completing an unlock request or had you just done a normal reset on your device when you got this error? Are you still on Sprint or migrated off to another carrier?