After the cinematics, u should see that you are equipped with infinity blade and go to Options again, under character slot, your new game+ should dissapear.
Now load the Original game from the same character slot.
I have tried starting a NG+ after continuing to level and my stats carry on instead of from the time I defeated godking so I am still leveling up now in OG to make my atk at least 200 before i try NG+ again. --- The Nu Gundam is not just for show!
If you don't want reset from rebirth1 (higher rebirth higher exp right?) try this.. 1. In character slot, u should see your NG+ current level 2. Choose new slot, create new character.. After create, it must have 2 slot (new character slot & new charater NG+ 3. Now your main character NG+ should be "new game+" without level stat 4. Before entering this new NG+ make sure in main slot character in full health ( for me more easy to fight garden Titan ) 5. Delete the new character slots ;p
It works for me to continued with last lvl and last stat.