I'm using the "IF/AND formula in the following syntax:

Cell U12 reads:
"=IF(AND(U9-"-",U15="-"),"-",DATA!R2)"

So basically if the cell above and below U12 have a "-" in them, U12 also
will display "-". If U9 or U15 has any other data than "-", then U12 will
display the value from worksheet DATA, cell R2.

I have this same formula in cells M12 and AC12, referencing the
corresponding cells above and below, referencing the same DATA worksheet
cell R2. They work just fine all the time.

Cell U12 will sometime (repeatable, on same selection) show the value of
DATA!R2 even though the cells above and below are showing "-" and should
return a "-" as well.

I can find no error in my tables, as the arguments for U12 are being
satisfied, yet the cell references DATA!R2 when it shouldn't.

Any insight?

Thank you.
Raymond