TFT- Losing LP, but not dropping in rank?

I'm not sure if this is a bug or not. I've had several games where I've lost my lp and dropped to 0 and then lost my game after that. It should demote me, but its not (even though I am secretly glad I'm not being demoted). I'm currently at Gold IV in my rank and because of my lost games, I should be at Silver I. I'm not sure if its a bug or not. I know during my climb I did actually get demoted a rank, but then proceeded to get better and climb back up.