Sell entries in IRA account not reflected in share balances

I had a lot of rebalancing trades in my IRA (TDAmeritrade is custodian) last month.  Three of perhaps a dozen SELL TRADEs downloaded from TDA did not result in any change in Share Balance.  The three mutual funds holdings, each of which was disposed of entirely, were still included in the Portfolio view.  I fixed the problem by manually entering the sales data from my paper end-of-month statement, witnessed the proper decrease in Share Balance to zero, then deleted the downloaded entries.  At last all was reconciled.  Mystery: what was it that caused these three particular downloaded Sell Trade entries not to be accounted for in the Share Balance tally?  [Quicken for Mac, subscription, up-to-date.  9/10/2018.]