MacBook Pro M2 Max issue with dual monitors

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joebobe Author

Level 1

4 points

MacBook Pro M2 Max issue with dual monitors

I have dual monitors, both connected through usb-c ports to my M2 Max laptop, each one with its cable.

Until a few days ago, it worked fine, but all of a sudden it stopped working:

If I connect both monitors to the USB ports, only primary external monitor (Dell Ultrasharp U2721 series) is detected and shows image.
If I disconnect the primary external monitor, then the second one (Arzopa portable monitor) shows image.
If I connect the second monitor to the HDMI port, then both external monitors are working. At this point USB-C is providing power but not signal, it can be disconnected and the monitor stills working if it has another power source.

Until a few days ago, I could use them with USB-C cables.

Is there any known issue that could be affecting this to work properly?

MacBook Pro (M2 Max, 2023)

Posted on Nov 25, 2025 11:37 PM

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Answer 1

Nov 26, 2025 7:15 AM in response to joebobe

There are a lot of reports of problems with those portable monitors.

Almost all seem to be problems talking correctly to the USB ports to get the desired features, both signal and power at the same time.

Some of tho=e makers have issued firmware updates for the display to get it to work better. Check with the display maker.

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Answer 2

Nov 27, 2025 6:41 AM in response to joebobe

Windows does not do any error checking, so LOTS of stuff appears to work under Windows, but fails when connected to a Mac, which is much more demanding of error-free operation.

The Apple standard for its built-in hardware-accelerated displays, makes them suitable for full-motion video for production/display of cinema-quality video with NO dropped frames, and NO dropouts or partial-blank scan lines due to memory under-runs or Transmit errors due to low-spec or overly long cables.

Your USB cables should be no longer than ONE meter, maximum.

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Answer 3

joebobe Author

Level 1

4 points

Nov 26, 2025 11:41 PM in response to Grant Bennet-Alder

Thanks for your answer.

Unfortunately there are no firmware updates at the time for my portable monitor (arzopa z1rc).

fact is that same configuration (same monitors) still working properly with my other laptop, a windows machine setup which I use everyday for work

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