Since the update on my tablet s5e back in April, it has not only has it stopped my sim card working (but works on any other device) but I cannot sign into my Samsung account, but can via browser, it just keeps taking me back to the sign in screen. I have done every step possible except reset my tablet completely.....because it requires me to sign in to my Samsung account to reset. I have also placed other sim cards in the tablet and they don't work on it either. O2 haven't been any help. Please help, I need my tablet for my business.