Current behavior: "Save As" and "Save a Copy" default to saving in the file format set as "Always save as" for the current Document Type Suggested behavior: "Save as" and "Save a Copy" should default to saving in the current file format. "Always save as" should only be used for new files (or as the suggestion when there is risk of data loss). Rationale: By far the most common use case for me is that I want to save in the current format, but with a different name and/or in a different location. If the current behavior is required/preferred by some users, I suggest that this is made into a setting in the File/Save options.
What desktop environment are you using? KDE? There is bug 92517 " KDE4-FileDialog: "Save as" has wrong Filter".
I am using KDE. This bug indeed seems to be a duplicate of the one you mention. Thanks. *** This bug has been marked as a duplicate of bug 92517 ***