Ok, you should name your folders "NIGHT_20210720" and "NIGHT_20210717", this is the correct keyword/value syntax to separate frames by NIGHT.I have a directory
NIGHT20210720 and inside that NIGHT20210720_Flat and NIGHT20210720_Light.
NIGHT20210717 and inside that NIGHT20210717_Flat and NIGHT20210717_Light.
the bias and darks are in a separated dir.
Keywords NIGHT20210720 and NIGHT20210717