IMatch deletes all files not only the selected ones

[frankdarwin]

I have 132 files in one folder, 66 of them are .nef files.
I do not need these anymore.
Therefore I have selected only the .nef files in the File Window in Search Bar.
After that also only the 66 .nef files are shown to me.
I selected these with Ctrl+A and then deleted them with Ctrl+Del.
After Crtl+Del also a message appears asking me if I really want to delete the 66 files. I confirm this with Yes.
Unfortunately I found out that IMatch did not only delete the .nef files, but all files.
This is not good!
Thank God I have a recent backup of all files. So I loaded the deleted files back and repeated the attempt to delete the .nef files.
Unfortunately with the same result.
How do I manage to delete only the .nef files?
Is there an error here?

[Mario]

IMatch does not delete files just for fun.

This sounds like you did setup a buddy file relation.
If the master is deleted, the buddy files are also deleted. Or renamed. Or copied. Or moved.
This is how this is designed to be.

So, check your buddy files setup.
If you don't know what this means, re-read File Relations: Buddy Files and check your file relations setting.