I purchased my Note 8 tablet on Amazon from a highly rated seller about 5 months ago. It is an unlocked At&t model. It was packaged in a new unopened box, seemingly never used before, but I'm not sure if it was refurbished or what, because I have been having a few issues with it. The most annoying and major one is the fact that it keeps shutting itself off when it's been sitting idly at random times, about 5 to 10 times a day. I do have a case with a magnet on it, now. However, it has been doing this since before I purchased the case... It has never shut off while I'm using it & it randomly does it no matter what percentage of battery I have remaining! Also, I can't just turn it back on with the power button... I have to reset it by holding the power button & volume up or down. Then, it comes up with 1 of 2 different screens: a warning about a custom Os installation that says, volume up to continue with custom Os or volume down to restart phone. I always choose the latter. The second screen has a list of options labeled Android system recovery 1. Reboot system now 2. Apply update 3. Wipe data/ factory reset 4. Wipe cache. I always choose to reboot the system. It is annoying! Help! I also have Trustgo antivirus & Cleanmaster antivirus & they haven't detected anything. Another annoyance, the MultiWindow option worked on two occasions in the beginning & hasn't worked since. Last thing, my touchscreen freezes randomly for about 5 seconds & I can't do anything. Please help! I've been searching Google & still haven't come up with any solutions. Thank you! 
