HDR on Multiple Monitors on Mac Mini 2018 using Monterey (v12.6.2)

Hello WandJT__,

That's a great question! To confirm, if you disconnect the display that currently shows HDR as an available option, does HDR appear on the display that remains connected? The reason we ask is to help isolate the issue and determine if this may be expected. Also, if you haven't already restarted your Mac, this is a great step that can help with resolving many issues. You can find the steps for restarting in the article below and outlined in the following article.

1. Click the Apple logo towards the top-left.
2. Click Restart in the menu that appears.

Shut down or restart your Mac

Let us know how that goes!

Hello WandJT__,

Thanks for the additional information. Here's some more information that we'd like for you to visit that can often resolve HDR issues with external displays. It's from the article Play HDR video on Mac - Apple Support but we've quoted the information below for your convenience.

Check your Mac

Install the latest Apple software updates for macOS Catalina or later. Some HDR features are available only with the latest macOS.

Choose Apple menu  > System Settings (or System Preferences), then click Displays. In Displays settings for the external display, make sure that High Dynamic Range is turned on. This setting appears only on third-party displays that support HDR10, not on built-in displays. If you don't want to use HDR on your external display, turn this setting off.

Choose Apple menu  > System Settings (or System Preferences), then click Battery or Energy Saver. Click the Options button, if present. If “Optimize video streaming while on battery” is turned on, your Mac saves energy by playing HDR video in standard dynamic range (SDR) while on battery power. To play in HDR, connect your Mac to power or deselect this checkbox.

HDR content might play at resolutions no greater than 1080p on Intel-based Mac mini, Intel-based MacBook Pro, and Intel-based MacBook Air models, depending on the HDR content and the display on which it is viewed.

Check your display

Some TVs support HDR only on a specific input, such as HDMI input 2 or HDMI input 3. Check your TV's documentation for details.

Make sure that your display supports HDR10. If the display has its own HDR setting, turn it on or set it to prefer HDR when available.

Make sure that your display is using the latest firmware from the manufacturer. Check your display's documentation for details.

In general, HDR quality is better on HDR displays that offer better brightness and contrast ratio, which results in a wider dynamic range. 

Check your media

If you're playing premium content from a third-party content provider, check with the content provider to be sure that they support HDR on your Mac.

Check your cables and other devices

If you're using HDMI, make sure that the HDMI cable and any adapter you might be using with it both support HDR10. Apple recommends HDMI cables that have been tested with Apple TV 4K and a wide range of TVs, such as the Belkin UltraHD HDMI Cable. Compatible adapters include the Apple USB-C Digital AV Multiport Adapter and Belkin USB-C to HDMI Adapter.

If your video connection passes through an AV receiver, sound bar, or other device before connecting to your display, make sure that the device supports HDR10 and is using the latest firmware from the manufacturer. You can test by connecting your Mac directly to the display.

Check your viewing environment

The brightness and color of HDR video might vary depending on your Mac model and the lighting in your environment. Lower lighting conditions, such as in a dim room, enhance the visual effect of HDR.

Check your network

The video quality of content that you stream over a network, including over the internet, is affected by the quality of that network. To stream high-quality video formats, you need a fast connection. Apple recommends a minimum speed of 25 Mbps for 4K streaming.

Have a great day!

Hi WandJT__,

Looks at the Tech Specs for your Mac mini 2018, it looks like only one display will support the higher resolution.

Video Support

• Support for the following combination of maximum concurrent display setups:

• Up to three displays:

Two displays with 4096-by-2304 resolution at 60Hz connected via Thunderbolt 3 plus one display with 4096-by-2160 resolution at 60Hz connected via HDMI 2.0

• Up to two displays:

One display with 5120-by-2880 resolution at 60Hz connected via Thunderbolt 3 plus one display with 4096-by-2160 resolution at 60Hz connected via HDMI 2.0

• Thunderbolt 3 digital video output supports

Native DisplayPort output over USB-C

Thunderbolt 2, DVI, and VGA output supported using adapters (sold separately)

• HDMI 2.0 display video output

Support for one display with 4096-by-2160 resolution at 60Hz

DVI output using HDMI to DVI Adapter (sold separately)

Mac mini (2018) - Technical Specifications

If we're still misunderstanding the issue, it would be best to contact Apple Support, so that can look at this with you.

Apple Support

Take care!