Create a Kdenlive project with some basic editing on the timeline and save the project. Create a new Kdenlive session an try to import this project as clip. Audio is not imported. Note that audio is imported when a 20.08 Kdenlive project is imported as clip in a Kdenlive 20.04 session Tested with 20.08.1 and 20.04.2c appimages on Ubuntu 18.04 and 20.04.
Thank you for reporting. I can confirm this behavior on Windows 20.08.1 as well.
If I remember well this has been recently fixed. Can you please test with the latest version (20.12.3 at the moment, https://kdenlive.org/en/download/) and close this report if it is not relevant anymore?
Great! Tested on Kdenlive 12.12.03a on Ubuntu 20.04 and it works.