I Just Finished a Workout but the RTT Score Hasn’t Changed

The RTT score will not be updated until there is a new HRV reading from Apple Watch.  If you chill out after the session then this should happen automatically when you are still and rested.

Or you can force it by using the Breathe app for a minute or more (just don’t do that while you still have an elevated heart rate from the session)

To check the time of the last reading scroll through the chart with the Digital Crown on Apple Watch.