Problems in connecting 3rd monitors to a Mac mini (M1 CPU version)

M1 MacMini can only support up to 2 displays --- https://www.apple.com/mac-mini/specs/

Vivian_Tam wrote:

...Could you help check this issue?...

As others have pointed out, this is not an issue, it is how the Mini is designed.

You should have read the specs before trying to use the Mini for something it was just not designed for.

It is possible to connect three monitors to an M1 Mac Mini, each showing a different scene (I.e. not mirroring). The following describes how I did it in a flight simulator:

X-Plane 11.53r1 on a 16 GB M1 Mac mini connected (a) To a Dell model 2007 FPS monitor (1600 x 1200 @ 60 HZ via VGA on monitor to VGA/DVI-I adapter to Startech.com USB 3.0 Dual Head Graphics adapter to USB-C on Mac mini), and (b) to a Westinghouse TV model LDD2240 (1920 x 1080 @ 60 Hz via HDMI to HDMI), and (c) to a Flatron W2252TQ (VGA ơn monitor to Belkin VGA/Thunderbolt adapter to Thunderbolt on Mac mini). DataLink driver from Startech.com was activated. OS is Big Sur 11.4. Logitech Saitek Yoke, Power Quadrant, Rudder Pedals, and Radio Stack. Flight Velocity Pro Trim Wheel. Mini iPad with ForeFlight mounted on the Yoke provides GPS position on a map (VFR, IFR, or satellite). Another mini iPad with Air Manager V.3.7 from Sim Innovations shows the instrument panel when I want only external views on the three monitors. I often switch to that view after completing pre-takeoff checklists and getting underway. 

The M1 Mac Mini only supports two displays,

see > https://support.apple.com/guide/mac-mini/connect-a-display-apd8e4fbbb97/mac

Simultaneously supports up to two displays:

• One display with up to 6K resolution at 60Hz connected via Thunderbolt and one display with up to 4K resolution at 60Hz connected via HDMI 2.0

+1

An easier-to-read and more in-depth explanation of the above post can be found by clicking on “Flight Simulator” at this website: https://sites.google.com/view/seangdwyerstem/stem-for-all-ages