What is your operating system?
What is your Shotcut version (see Help > About Shotcut)? Is it 32-bit?
Shotcut 25.05.01 and is 64-bit
Can you repeat the problem? If so, what are the steps?
(Please be specific and use the names as seen in Shotcut, preferably English. Include a screenshot or screen recording if you can. Also, you can attach logs from either View > Application Log or right-click a job and choose View Log.)
When I add a 2nd video track and then add my logo and add filters to Fade In Video and Fade Out Video, a black box appears before the image fades in and also appears after fading out.