Is Luck Broken in bl3

Hi I have been playing this game every day snice it first came out besides the story line, I love this game.
I have been farming for everything and I notice no changes in drop rates from tvhm or normal mayhem 3. I have even increased my luck to 14.97 now I used a load dice no changes in drops I even used a 12.67 luck Artifact no changes in drop rates I was wondering if the luck is broken or not working correctly. Also DPJ did a video on YouTube about 12.67 Artifact and none Artifact drop rates.