How can I prevent brief brightness dips during direct XDR upscaling?

For a compatible built-in XDR display using direct brightness control, keep Force EDR mode during direct brightness control enabled. It helps prevent momentary brightness changes when macOS enters or leaves extended dynamic range after HDR content.

Find it under Settings > Displays > [built-in display] > Device Control > Additional Apple Brightness Settings…. The option is on by default and requires Pro. The additional settings appear when direct control is allowed.

This setting applies to Brightness Upscaling (Direct). Continuous software XDR upscaling readiness is a separate setting for software upscaling. Use the setting that matches your active method. Keeping EDR active for direct control may also force other external Apple displays into EDR mode.

If brightness still fluctuates with this option enabled, check whether the change happens only around HDR content or also during ordinary use. A lasting loss of brightness may have a different cause. See Apple direct brightness settings for the control range and prerequisites.