Report Builder will display the values in the order they are stored in the SPSS file. SPSS 23 (and maybe earlier versions) automatically sorts them. I'm guessing your data file was produced using a third party utility rather than SPSS itself. So if you were to open the data file in SPSS and re-save, that should re-order the value labels and they will appear in ascending order in RB.
I wonder if RB should automatically sort them, or at least have an option for that. What do you think?