Mac OS X 9_2_0 (Chase?)
I just closed my account, so can share that I had this same experience with Chase, who was supremely unhelpful (by both email and phone) trying to explain this. Also a Windows NT 10 OS showed up in device history, which I don't own. Daily access.
My theory is it's a system error on Chase's end, not actual access, but I'm done with Chase either way.
Posting here for future people who have this issue. I asked a Chase rep to create a ticket and file this as a system bug, but mostly the rep just seemed annoyed, so we'll see.