SUMMARY

When moving several tracks at the same time, especially in large projects, the operation has a lag of several seconds, while the app is unresponsive and then, the tracks are shown at the new location on the timeline, to which the drag occurred.   




STEPS TO REPRODUCE
1. Fill in several tracks with media for the length of about 2 hours
2. Trim a section in about the middle of the tracks, with trim points on top of each other
3. Select Spacer tool from toolbar or press M and then drag the beginning of one of the tracks and try pushing it forward. You'll notice the lag. 

OBSERVED RESULT

You'll see the lag while dragging multiple tracks. 
EXPECTED RESULT


SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma:  Fedora 34
(available in About System)
KDE Plasma Version: 
KDE Frameworks Version: 
Qt Version: 

ADDITIONAL INFORMATION
Kdenlive AppImage 21.11.70