Can you provide some more detail?
What operation type?
Does the tool path look correct on the screen?
Is the tool path listing showing the right values?
What postproecessor are you using?
You are also welcome to call GTAC - they are great at asking all the right questions to get to the bottom of the issue.
Operation type- Finish turn OD
Operation looks as if no offset is applied on the screen
The listing is not showing the offset
Postprocessor is UGPost
We don't know of any issues in the tool path calculation in combination with grooving tools. This should work normally if the settings are right (tool tracking point needs to be defined in the tool, tracking point needs to be selected in the operation, plus tool orientation settings need to be correct).
We really need more information to figure out what's going on, so please contact GTAC so they can get the details.