Unable to configure APN "This APN is not allowed on this device"

[PhoneUser578]

I've been using my Samsung Galaxy S8 (SM-G950U) for over 2 years with Lucky Mobile, all's been working fine.

Last week, I went to the USA and bought a SIM to get some data over there (ATT). I noticed when I installed it the phone rebooted and reconfigured itself (I noticed some added ATT bloatware I didn't have before). When I got back and reinstalled my Lucky Mobile SIM, I didn't have data anymore. I tried a factory reset, but it "resets" to the same  "ATT" version. When I try to configure the APN as per instructions in the site (which I think is the issue) I get the error message "This APN is not allowed on this device. Please try another one.". Seems like the ATT version of the firmware doesn't play well with other APNs.

So, how can I bypass this check to correctly configure the APN? or alternatively, how can I revert to my previous version of the phone I had before which didn't have this APN allow-list issue?

Thanks!

[LuckyMobileAntgio]

Hey there @PhoneUser578 , 

Welcome to the Community and thanks for your post. 

We've found the following on Samsung.com that may help you with your concern; Check out Reset APN Settings on a Samsung Phone to learn more.

Let the Community know if you have more questions.

[PhoneUser578 · Accepted solution]

Hey there. Thanks for the tip, but I had already tried this and it didn't work (it added 2 APNs, none of which where the one I needed for Lucky Mobile).

That said, I did manage to get my phone working again by doing re-flashing stock firmware using Odin.

Thanks.