I assume you're using a TV with Discrete Power On and Power Off codes, (not that that is immediately relevant).

Can you program (alias) the TV IR commands onto a separate button and work the TV from the remote that way? If that works, the problem might be caused by the macro sequence.

Is the TV Power code the first step in your macros or are there other commands that the remote emits before it? You might try moving the code around; adding a delay before and after it; or (if it is a discrete command) sending it twice in a row.