All rows in column F seem to be working correctly.
In rows where column B contains "Work", column F contains a copy of the data in column C.
In rows where column B contains other text, column F is 'blank'.
The exception in the last two rows occurs because column B is empty. Many functions will assign the numerical value zero when coming upon an empty cell, and you'll note that this happened in these rows of column F in your table. Conditional highlighting rules assessing text do not recognize "0" as being the same as "" (the empty string), so those cell are not highlighted.
Regards,
Barry