Help with screen recording 60FPS using AMD GPU

I have an RX580 and RX 5500XT, and my desktop has Kubuntu 20.04 installed. When I use SimpleScreenRecorder, or OBS, the results are very choppy (around 15FPS). I posted an example some time ago on reddit here:

When I use an Nvidia card (a 1070) on the same PC, screen recordings are very smooth (full 60FPS) - even when not using nvenc. Everything is also very smooth when using the Intel iGPU.

Is it possible to screen record at 60FPS on Linux using an AMD GPU?