When downloading images and pictures from websites, the file type (JPG, GIF, PDF, etc.) is not copied from the original file.
Please see post from @eljuno below. You can track this issue from there. We’ll close this thread -please open new threads for any other items you encounter. Thanks for your feedback!
If I’m not wrong, this is a known issue if the file name is changed. Is this the issue that you encounter?
All I can recomend for now is to add it manually (.jpeg, .png, .pdf, etc) after the file name is changed or save it without changing the name. Issue is logged for this and can be tracked here: