I got through to TurboTax's phone line Susan and they solved the problem.
For anyone else reading this thread, here's the issue.
On the RSP profile page one of the questions is did you open an FHSA. I ticked yes but because it was opened in 2023, not 2024, I should have left that box unticked. Ticking the box appears to tell the program there is no 2023 carry over and appears to block your efforts to enter that carry over contribution room.
Cheers.
Doug.
