How do I make macOS remember projector color settings?

I'm fighting with macOS over Epson EH-TW450 projector color settings. When I go to Settings → Displays → Display Settings → Colour Profile → Projector..., I get a nice panel for adjusting the projector gamma and white balance: The problem is, after I move the slider up, which makes everything brighter (good!), the projector brightness smoothly goes down to the original level over the next few seconds. The slider stays up, but the brightness isn't the same. When I click the slider again (without moving it), the display becomes brighter again, but again only for a while. How do I make my Mac remember this setting? I also tried various color profiles from the list, but none of them gives me the brightness I want and I also didn't find a way to control the gamma manually. And my projector has no brightness/gamma setting either :( I'm using macOS Monterey 12.4.