Yes, it will turn off and on, with the tank off it shows 9.9 and full battery charge, with the tank on the resistance indicator flashes.
It sounds like the mod is working OK. Based on your other answers, it might be that the 510 connector is flaky between the mod and the tank. On the bottom of the tank there is a metal pin pushed up into the insulator. With a small flathead screwdriver, try to pull that pin out ~1 mm, then replace the tank back on the mod. With that pin out a little bit, it should make good contact with the 510 connector in the mod. I've had this problem before by over tightening the tank onto the mod. It only needs to be snug to make a good contact.
EDIT: I have confirmed that a flashing ohm indicator means that it's not making a good 510 connection. Another possibility is that the 510 connector in the mod has been pushed down. Have you put any other toppers on this mod?