Unfortunatlely, uninstalling and reinstalling the QB app on my iPhone did not help on either of the two separate times this problem occurred.

The only way I was able to resolve this QB phone app error on both occurrences was to log into QBO on my PC and review the large number (approximately 100 more or less) of freshly snapped receipts.  The QB phone app problem did not go away until the number of remaining receipts For Review on QBO on my PC got small enough (sorry, but I did not check the number of remaining receipts) that I could then view the remaining receipts on the QB phone app.

The next time I have a large backlog (hopefully not) of receipts to snap, then I will make a point of stopping after a few dozen snaps on my QB phone app to Review the newly snapped receipts before snapping more.