I cannot confirm this with Ubuntu Trusty and Xenial.
Some ideas:
* Wich waveforms and which Skin do you use?
* Does this happen with the preview button coloumn hidden?
* What is the CPU load during the issue?
* Do other applications react normal?
* You may also try the branch which removes the qt4 scaling.
* Which OS and qt version do you use?
I cannot confirm this with Ubuntu Trusty and Xenial.
Some ideas:
* Wich waveforms and which Skin do you use?
* Does this happen with the preview button coloumn hidden?
* What is the CPU load during the issue?
* Do other applications react normal?
* You may also try the branch which removes the qt4 scaling.
* Which OS and qt version do you use?