This was the bug and it is resolved in the 2023R2.
Edit the system environment variables in the search window of your system, then click environment variable, select a new user variable in the user variable, type the variable name ANS_USE_OPENGL_LEGEND_EDIT, and set the variable value =1 then apply this setting in the system.
I would recommend to restart the system and then open it. You will be able to edit it on your system.
Regards,
Sampat