I have used darktable for a couple of years, processed several hundreds of pictures, and now I’m stuck, as I cannot seem to select pictures through collections anymore. Yes, I can enter film rolls, folders, whatever, but whatever I do, the collection in the light table is stuck on one collection which does not match my collection query. Am I overlooking something trivial, or did I hit a nasty bug?
What version of darktable and which OS? Can you start darktable with darktable -d all and paste the output here?