3DS doesn't charge unless I switch to a different outlet?

Really weird issue. My 3DS charges perfectly fine, but when i go to charge it again at a different time, it won't charge unless I swap outlets. It's not the outlet itself that's the issue cuz:

-Charge system in outlet one

-unplug and play until low.

-go to plug it again to outlet one but no light, so i change to outlet two

-unplug and play until low

-go to plug to outlet two, no light so i change to outlet one and it charges just fine

What's going on here? Anyone with technical knowhow able to tell me what's going on?