I finally figured this out after reading through gazillions of (unhelpful) CSA responses. I noted one USER @awmazinglyyou who had the answer, so responding here in more depth in the hopes it helps someone else, as the moderators' responses are so infuriating (looking for duplicates or checking to see if the transaction is "really" reconciled, send us feedback, call CSA, or (slit my wrist) "ask your accountant").
It turns out that if a transaction is booked to more than one Balance Sheet account, it will look at both of those balance sheet accounts to see if they are reconciled. If a transaction hits your bank account, and the offset is another Balance Sheet account, unless you reconcile the 2nd balance sheet account, the trans shows up in that "unreconciled" list. You can recon the bank account all day long, but until you reconcile the other balance sheet account, it will be there in that list.
Example: I did a major cleanup for a client that had no idea what they were doing. My JE to fix the mess was to DR the bank account and CR Owner Draw. Even though I had done a recon of the bank account, marking the DR associated with the cleanup JE as part of the recon, the transaction still showed up in my "Unreconciled" list during the Books Review. I don't have any idea how you would reconcile Owner Draw, but based on ONE brief post I saw in this thread, I proceeded with a recon of the Owner Draw account, entering $0 as the balance. Then I marked the CRs of the cleanup JE to see what my reconciliation "difference" was. I then edited the Owner Draw balance per the recon = to the "difference" and was able to recon Owner Draw. When I went back to my Books Review and looked at the Unreconciled list, the JE was no longer there.
Hope this helps someone, cuz the canned responses re: how to reconcile your bank feed or (God help me) ask your accountant are worthless all.day.long.
