Macbook mini M2 Dell monitors disconnect after login when using HP USB-C/A universal dock G2. When I connect my Macbook Air M1, monitors are fine.

Forson100 wrote:

I have a mac mini M2 8GB ram. I also have a macbook air m1. I have two 1080HD desktop monitors from Dell, one of which connects using HDMI, one which uses Displayport.

I connect my mac mini the monitors by using a HP USB-C/A Universal dock G2 using DisplayLink.

Both displays connect when I start up my mini and I see the Apple login screen on one of them. As soon as I sign in, however, both monitors go black and display errors indicating that they have lost connection. No image can be restored while they are connected to the dock.

When I move the HDMI cable from the dock and connect it directly to the mini, that monitor connects and I can use my mac as usual, but only on screen.

The dock does not indicate that anything is wrong. The power light stays illuminated.

The dongle for my mouse is also plugged into the dock. My mouse continues to work, and it recognises that only one screen is working (i.e. there is no funny business where it leaves the screen as if travelling to the next monitor).

When, instead, I connect my macbook Air M1 to the monitors using the dock, everything works perfectly, all day long.

I have updated the firmware on the dock using a windows machine. I am using the latest version of Displaylink (1.10.1 (build 93)).

Has anyone any idea why my mini (which can, ostensibly drive up to three monitors) loses connection when connecting to two monitors when my macbook air has no problems?

According to the specifications, the M2 Mac mini can only drive two monitors. It is the M2 Pro Mac mini that can drive three.

Macs don't support DisplayPort MST daisy-chaining. To connect two displays to a single Mac Thunderbolt port – on Macs that support multiple USB-C / Thunderbolt displays – the device connected directly to the Mac must be a Thunderbolt device, like a Thunderbolt dock. I'm guessing the HP dock is a USB-C one but not a Thunderbolt one.

Furthermore, since you are using the DisplayLink "workaround" to attach two monitors to a machine (M1 MacBook Air) that only supports a single monitor, have you considered the possibility that some of the video outputs on the "HP USB-C/A Universal Dock G2" are set up to work ONLY with DisplayLink – whether the computer connected to that dock can support multiple displays, or not?

You might have to run DisplayLink on the Mini as well as on the Air if you insist on connecting multiple monitors to the Mini through that dock.