I had the same problem and was emailing where I bought it from trying to get a refund or credit towards another mod because this box is definitely got problems. I also was using the smok TFV4 tank and put in a brand new titanium coil so there was no need for worries about a bad coil build but every time I set it to titanium it came back to temp mode. I even tried setting the resistance with no luck. Then I finally clicked on one of the menu options that let me pick between watt mode and temp mode. I put it in temp mode then went back into the menu and changed it to titanium coil. Now I am vaping in temp mode with titanium coil, dual coil, and even the correct resistance. I still don’t like this mod. I love the smok brand but this mod is too problematic for my taste. When I first opened the box and put batteries in, it did not turn on no matter what I did. Finally after changing out batteries for about the fourth time it came on and I have been watching it to act up ever since. I am trying to return it because I only just got it a few days ago and I don’t want this mod, I should have gotten the snow wolf 220 watt. Whatever you do, do not get a joytech cuboid. They have an issue with the 510 connector and it keeps giving no atomizer or atomizer short when nothing is wrong except the pin in the connnector where you screw on the tank. You can take the tank straight off and pot on another mod and it works fine but put it back on the cuboid and get error message. Mine went out just a few days after warranty expired and now I can’t even get the company to repair it if I pay. No one will touch it and I found this is a common problem for the cuboid. Look on you tube at some reviews on this smok r200 and see if you can get some kind of answer. I have found a lot of useful info there and I used to never watch you tube but there is some really good reviews and info to be found there. Good luck with your mod. I think we both would have been better off buying a different mod, but you know what they say about hind sight.