I bought a refurbished S23 Ultra off Back Market and it is still on Android 14 and says my system is up to date when I try to update to Android 15, despite the security settings saying otherwise. The same thing happens with Google Play system update, which hasn't been updated since June 2024. I know the S23 Ultra is compatible with Android 15 so clearly something is wrong.
I checked the service provider software version and the active CSC seems to be CPW, which is Carphone Warehouse I believe. Might this have anything to do with my issue?
It is an international model from the UK. If it is possible to still return the phone, you should so so. The only way to fix this is to go to a authorized Samsung service center and have the phone flashed to get the proper software for the US. This will incur a fee, depending on where you are located it can be expensive.
I had a similar issue, purchasing my S23U from Back market, as well. I installed Samsung's Smart Switch on my computer and connected the phone to it, and then I was able to update from Android 14 to 15, then 16. Once that was done, I was also able to receive monthly security updates.
I'm having the same exact problem with my S23 FE. It's a dual SIM and eSIM model and it is carrier UNLOCKED but the phone is originally from Metro by T-Mobile, I tried using a new account on a eSIM since Metro by T-Mobile is the original carrier for my phone but I still didn't get an update. I'm still on One UI 6.1 Android 14.
