Daniel wrote...
I did looked at that, however LOOKUP does well for the first 8
rows, then for the 9th and 10th it crashes?
....

A stopped clock (of the old mechanical analog variety) is right twice
a day. This is the formula counterpart. Your formula works sometimes
due to pure happenstance. And if the values in your col F range
varied, you'd see that your formula actually only works reliably for
the first 6 rows. LOOKUP("TLOW",G4:G13,F4:F13) actually returns the
value of F13 rather than F10.