2nd life In hardcore

I was able to get 2nd life in Hardcore

When I died on hardcore I decided to take a picture of everything I built and turned on cheats and accidentally turned on survival and I had a second life

How to repeat the bug:
1. Press escape

2. Open item online play

3. Enable cheats and make the world online

4.Switch the game mode through f4 + f3

Perhaps this bug exists on older versions