I just updated Nik software to V 2.5 on a Windows 10 machine. I noticed that when I open Silver Efex with a new image it has retained the settings (Lightness,Contrast, film type, grain level, etc.) and control points of the previous image. This did not occur with the previous version of the software.
Sandy, this might be explained if you had created a custom “recipe” in an earlier session - which then determines default settings in a subsequent session.