No, I'm trying to use mobile data with other sim, not Sprint.
What do you mean by try the SIM for the new carrier? Sim has only one carrier where it can be used. Otherwise it's roaming from abroad.
What's the point do not give options to adjust the APN settings for already non Sprint or unlocked phone?
How APN should be set for mobile data use in this case?
We do not allow the alteration of APN. Not all phones work on all networks. What may work perfectly on Sprint may not work on other networks. Once we successfully unlock the phone for you, Sprint is no longer in control of any aspect of the device unless you happen to have it get relocked back to the Sprint network. Sometimes with LG phones this can happen when you update the device's operating system. If that happens, just reach out to us and we'd be glad to assist.
Once we've successfully unlocked your phone, you need to make sure that your new carrier has your IMEI and your SIM ICCID (for the new carrier) sync'd up on their side so that your phone and SIM register with that carrier network. That is the absolutely point 1 to start at if you are having service issues after getting your unlock completed from Sprint and popping in your new SIM for your new carrier. If your new carrier don't have both of those things tied to your account, you're going to have problems with services not working correctly. Again, you could also have issues with service if the device isn't fully supported on the new network, but that is something you'd have to review with your carrier.
Let me know if you have any questions.
The phone is supported in a network if it has appropriate frequency bands. All other compatibility discrepancies are just software issues. Thus, wideband phones are supported in all networks.
You are saying Sprint is no longer in control of any aspect of the device when it's unlocked, but in the same time for unknown reasons Sprint wants to block apn settings in the unlocked already non Sprint phone and limit its functionality by disabling mobile data. That is strange to me.
If i can make calls it's for sure my phone and SIM are registered with the carrier's network.