Looks great, functionality questionable

Product shipped reasonably quick. Able to make phone calls, text, obtain 4G/WiFi capabilities. Major concerns: I keep getting a security notification saying, "Unauthorized actions have been detected. Restart your phone to undo any unauthorized changes". It doesn't directly affect the phone's function, but it is annoying and I've tried a number a ways to get rid of it with no luck. Restarting the phone does not get rid of the message. Also, I installed a Straight Talk SIM card, but S4 occasionally says that it doesn't detect the SIM card. This particular issue affects functionality because it drops calls/text messaging when the SIM card is undetectable. I'll give it another week or so, but if my parents bring up these concerns again, I might have to return this product. Bought this phone for my parents. If they tell me these two concerns areRead full review

Verified purchase: Yes | Condition: New