Definitely a bug! I just tried to reconcile previous month and found more than a year's worth of reconciliation gone! I do not download from bank. Always manual. Have used QuickBooks for almost 17 years, and have never experienced anything like this. I am using the Desktop Pro 2017 version, and I think the last update must have messed something up. I have read all the entries on this topic, and quite frankly, I am afraid to try any of the fixes lest something else go wrong. Ugh.