I downloaded this program for its duplicate file finder & delete function. However, I have noticed that when I use the "Select duplicates in" option, and select a single subdirectory, it UNchecks all of the selections in other subdirectories. The only way I can use this option is by deleting files one subdir at a time.
This bug is replicable, sadly.
I'm not so sure that is a bug.
It's probably intended to give you an opportunity to think about what you are doing.
Duplicate Finder makes searching for duplicates easier than doing it manually.
But there is no way that it can know which duplicates are needed by applications.
And it can't know which of your own files you want to keep or not.
For that reason the deletion options are deliberately limited - and you should be very careful when using them.
I'm sure that you would rather take a bit of time to be sure that you are only deleting duplicates that you don't need/want, instead of letting a programme delete things that you do need (or want).