I'm having the exact same issues. Intel i7 8700k 16 GB Ram Nvidia RTX 2080 I can use the app for 2-5 seconds before the mouse is lagging and the whole performance is degraded. It comes back for 2-5 seconds and then the performance decrease again I've tried uninstalling drivers, affinity designer. Tried every combination of changes in the performance tab and nothing works at all. Not sure what to do anymore and I'm forced to work in Illustrator as it is not showing any of these problems.