What is your Shotcut version (see Help > About Shotcut)? Is it 32-bit?
20.04.12
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.)
varied operations: highlighting something on a different video track, overlapping for x fade… I’ll attach the log.
Your version is 8 months old. There have been 6 versions since the one you are using. Download the latest version which is 20.11.28 and see how that version goes for you.
Also, since you only have 8gb of RAM make sure to use Preview Scaling and Proxy and see if it helps you: