Disabling auto brightness on AMD

I’ve just installed a completely fresh Ubuntu onto my FW13 and am noticing a really annoying brightness-adjustment feature based on the screen contents. When the screen is mostly dark stuff the brightness decreases, when it’s mostly bright stuff the brightness increases. The transition isn’t smooth and it happens a few seconds after e.g. changing window, so it’s very distracting.

I want to emphasise, this brightness change is not based on the ambient light level detection, which can be disabled in e.g. GNOME settings. It’s based on the contents of the screen.

How can I disable it?

I can find plenty of resources about disabling this for Intel FWs on Windows:

Even a knowledgebase article calling out the feature specifically:

But I can’t find anything for AMD.

Can anyone help?

Framework 13 AMD Ryzen 7840U
BIOS version: 3.03
Ubuntu 24.04.1 LTS

I suspect you’re going to want to turn this off: