Why is a resolution missing from the slider or Display Mode list?

The slider and Display Mode menu filter the modes macOS provides. A mode can disappear from a filtered view when the current refresh rate, bit depth or HiDPI state changes, even though a size with different properties remains available.

For the underlying rendering method, see what flexible scaling and custom resolutions change.

Open the display's Display Mode > Filter… and inspect the refresh-rate, HiDPI/LoDPI, aspect-ratio and bit-depth selections. Select another rate or use Show All to inspect the wider list. These filters only change what is shown. Selecting a mode row changes the display configuration.

The resolution slider preserves the current refresh rate, bit depth and generally the current HiDPI class. It also respects configured size limits. Use the full mode menu when you need to change more than the desktop dimensions. Two entries with the same width and height can have different rendering quality or refresh rates.

Show All cannot create a mode that macOS has not exposed. It also includes unsafe or invalid entries, so visibility is not proof that a mode is suitable. Modes below 720 pixels high remain subject to the separate low-resolution filter.

If an app changes your display mode and the desired combination is no longer available, configuration protection cannot manufacture that missing mode. First establish whether the mode is filtered out, available with different properties, or absent altogether. See Display Mode filtering and HiDPI limits.