66i not reaching 100% charge

Picked up a 66i last night and charged it overnight (12+ hours). In the morning when I picked it up, I noticed that it was still at 99% battery. I tried unplugging / plugging it back in, powering it on and off, etc, but it just remained at 99%. Curious if anyone else has encountered this? I understand the functional difference in use of 1% is minimal, but I just want to make sure it's working as intended before I pass the return window. Thanks.