Increased Rarity item is not working

Hello,
This is my first time posting anything, so I am not sure how this works. However, I just wanted to mention that I have five items on that are supposed to increased the amount of rare items I find and that drop from enemies, and they don't seem to be working. I have a over a 100% increase in increase rarity items found and I seem to find less rare items when I have the gear on compared to my other gear. Honestly it doesn't just seem to be the case. I am almost certain I find more with my regular gear on than when I have the increased rarity gear on. Can someone help me with this?