I have a Galaxy S5 on T-Mobile SM-G900A Baseband G900AUCU2AOA1 that is unlocked but was genned for the AT&T network.
When i try to update the OS from 4.4.4 it says checking for software updates and stays there then i see a message display at the bottom “failed to validate the product key” then disappears .
When I look at notifications under Device management it says “Downloading software update. Please do…”
Any ideas as to why I can’t update this phone OTA? Also is there a way to bypass the 24 hr delay when it says phone is up to date?