You're right, that wasn't very clear. They weren't meant to work
together...

If they work after re-entry, then they didn't match prior to re-
entry.
Re-entering the same info into a cell will prompt Excel to convert the
data into the data type and format it thinks it is, unless the cell is
formatted as text. So re-entering the data may change the data type.

To "re-enter" data, you don't have to type it back into the cell -
just select the cell, hit f2 then enter.
This is a tip, just making sure you knew you didn't have to type every
character into cells, you can just enter edit mode with f2 to "re-
enter" if the issue is the data types not matching between the lookup
value and the lookup table. Of course typos are an entirely different
matter.

Cliff Edwards