Looking at the rtd file you sent the cover is displayed as 20 mm. Could you sen the rtd file where you have it displayed as 0 mm in the calculation note?
Thank you for the file. As far s I can see the 0 values are displayed when covers are locked. As you have the reinforcement frozen calculations of the beam will not change it therefore you can unmark these check boxes to have the correct value displayed in the calculation note.
1. Calculate beam with the fixed covers
2. Edit the value of covers in the calculation note or
2a. Freeze the reinforcement generated for the fixed covers
2b. Calculate the beam with frozen reinforcement again to have the 20 mm cover displayed in the note.