What I forgot to include in my question was that I use Shotcut to generate the xml-file for my project, which i run through qmelt on a server in order to move the load away from my laptop.
When i use your advice in Shotcut running on my laptop it works. But when i send the xml file to qmelt and let it render the project, i get the problem mentioned.
Am I missing some setting or…?
Do you have any hard-coded parameters in the qmelt script that could be conflicting? Is qmelt the same version as the Shotcut that generated the file? The MLT format evolves a little over time.
A diagnostic step could be doing an export on the laptop, right-click the finished job in the Jobs panel and look at the logs, then compare those to qmelt logs to see if there are differences.