The Part L compliance report may show a different Ground Floor U-value to that set in your Material Data.
This is not an error or a software issue - it is due to the projects Part L settings, and the SBEM calculation methodology.
To implement user defined values in your materials and constructions, go the the Materials section under Data Managers Tab, and tick on the user defined value settings within the construction details as below:
Once the values are set, go to the Part L calculations and move to the General Tab. Under the Others section, tick U values for ground floors have been modified in accordance with BR 443:2006.
This will allow the software to consider the user defined U value in the Part L calculations and the same would be reflected under the compliance report.
To know more about the new essential changes in Part L 2021 regulations, please refer to the article here.