Created attachment 107104 [details] I click on the corner of the clip, hold it, and drag it to the upper track then it's the bug. For detail, please see the attachment and if not convenient, the attachment is also available at "http://klsztx.nos-eastchina1.126.net/Bug.webm" temporarily. In the video, I click on the corner of the clip, hold it, and drag it to the upper track then it's the bug. Thanks
The issue should be solved. Please try with the current Kdenlive AppImage version 19.08.0a to see if there are any packaging issues https://files.kde.org/kdenlive/release/ If the problem/issue doesn't occur when using the AppImage, then it's your configuration or packaging.
I cannot get to my laptop right now, but I do see it fixed sometime. I will mark this bug as RESOLVED and FIXED, thank you very much for bringing such great software to us.