Why does HDR disappear at some HiDPI resolutions or refresh rates?

macOS can offer HDR for one display mode but not another, even on the same HDR-capable monitor. The complete combination of desktop size, HiDPI scaling, refresh rate and connection matters. On supported Apple silicon connections, Forced HDR may make additional combinations usable. Test the result on your setup.

For the rendering background, see how macOS scaling, HiDPI and LoDPI work.

First try a smaller HiDPI desktop or a lower refresh rate and check whether HDR becomes available. This helps separate a mode-specific restriction from a display or connection that does not offer HDR at all. The monitor’s maximum refresh rate may be available only for some modes.

Trying Forced HDR

With Pro, open the display's Color Mode menu and enable Allow Forced HDR, if available. This makes additional HDR choices available. It does not turn HDR on by itself. Use the display's HDR switch, marked Forced when appropriate, or select a supported Forced HDR color mode. Confirm the resulting resolution and refresh rate afterward.

The option depends on the modes the Mac can find for the connection. It does not create HDR support in an SDR monitor or remove bandwidth and rendering limits. See Color Mode for the available choices and HiDPI refresh-rate limits for the rendering distinction.

Keeping a working mode after wake or input switching

Once the desired combination works, enable protection for HDR Status and Refresh Rate under the display's Configuration Protection. If you also want to retain the desktop size, protect Resolution. Check the saved values after making manual changes, because selecting a new mode can update what is protected.

Test both sleep/wake and switching the monitor away from and back to the Mac. Protection can restore only modes that remain available after reconnection. If the display falls back to a different rate, inspect the current mode list before changing it and follow refresh-rate protection troubleshooting. Repeat these checks before relying on the mode for daily use.