Compatibility of external monitors with 2021 MacBook Pro

@bjvan75 I'm seeing those issues as well. I operate in clamshell mode, but if the computer goes to sleep I can only seem to wake it using the Apple Magic Trackpad. It doesn't seem to wake from other connected devices. It will also wake, then sleep, then wake again and be usable after the second wake. This isn't the case on other machines, which work fine—perhaps ultra fine.

I've started a separate thread here in case anyone wants to follow.

When trying to use a USB device plugged into the display:

1. Plug the device into the USB hub on the display via a USB cable with a USB type C connection.
2. Expect one of two outcomes:

a. The device plugged into the display is unresponsive and unrecognized, or

b. The device receives power, is briefly recognized, but ultimately loses power and is unrecognized. This may be a few seconds, a few minutes, or even a few hours.

Then, frustratingly scour the internet for a solution.

The trouble isn't just with the USB hub on the display.

When trying to use the built-in camera on the display:

1. Start a video conference call with the display connected over Thunderbolt.
2. Select the built-in LG camera as the desired video camera.
3. After a few minutes, the camera will fail and no longer be recognized by the MacBook Pro.

The camera and the USB hub appear to fail at roughly the same time.

I've found at least one other person with this exact same issue. Interestingly, both of us have 14" M1 Max machines and both of us have Wacom tablets connected to the USB hub on the display. I've tried installing older drivers for the Wacom tablet to see if that would affect anything—it doesn't.

The display works perfectly fine when connected to a 16" Intel MacBook Pro. The display also works perfectly fine when connected to a 13" M1 MacBook Pro. The issue is with the 14" MacBook Pro M1 Max.

Don't skimp. Neither RAM nor drive can be upgraded after it is built.

also, the built-in display is nearly the same number of pixels as a 4K display. You paid dearly for that nice display, don't shut it! Use Extended Desktop to combine both displays:

I have a 14" M1 Max and 5k LG Ultrafine. I'm having a heck of a time getting the display to function properly.

I initially did a migration from an Intel 16" MacBook Pro. After experiencing a ton of issues with both the display and software, I learned others were also having trouble with the migration assistant. So, I erased the machine and rebuilt with recovery assistant to start from scratch.

The display still doesn't work. The issues specifically surround the USB ports and camera. The M1 Max machine is having difficulty recognizing both. The USB ports may work for a few minutes, even a couple hours, but will ultimately be unrecognized. The camera usually fails after about 15 minutes on a conference call.

I'm on about 6 hours of calls a day that require a camera. I use a mechanical keyboard and Wacom tablet that both rely on the display's USB hub. As it stands, the nearly $7k M1 Max is not usable as my daily driver, so I'm back to the 16" Intel machine until I find a fix.

It is a Thunderbolt Display.

I've tried various connections. My default setup runs through a CalDigit TS3 Plus. Thinking that's where the issue might be, I bypassed the dock and connected directly from the MacBook Pro to the LG Ultrafine with various ThunderBolt 3 and Thunderbolt 4 cables—nothing worked.

I also have the MacBook powered by the MagSafe cable in an attempt to reduce as much responsibility as possible on the Thunderbolt connection.

<< I bypassed the dock and connected directly from the MacBook Pro to the LG Ultrafine with various ThunderBolt 3 and Thunderbolt 4 cables—nothing worked. >>

WHAT? if that display is working properly, how could that be?

✅ Tried various Thunderbolt 3 and Thunderbolt 4 cables. Even bought new ones.

✅ Tried various USB cables plugged into the display's hub.

✅ Checked the firmware version of the display to make sure it's up to date. It is.

✅ Erased the Mac and started from scratch. No help there.

✅ Tried all 3 Thunderbolt ports. Behavior is the same across all ports.

Something just isn't right. This is the only display that represents some sort of middle ground between consumer displays and pro displays. I hope we get to a resolution soon.

so the display lights up fine, it's just the USB peripherals that fail?

have you tried the same experiment with the Wacom tablet disconnected?

are you using the power supplied by the display to run your Mac?

so the display lights up fine, it's just the USB peripherals that fail?

The display panel itself works, yes. No, it's not just the USB peripherals; it's also the camera and the speakers. Basically, everything but the display panel itself fails.

have you tried the same experiment with the Wacom tablet disconnected?

Yes. The same thing happens. Whatever is plugged into the display hub will ultimately not work. You can plug these devices, such as a Wacom tablet, directly into the other Thunderbolt ports on the MacBook and they work just fine. External devices also work when plugged into an external hub like the Caldigit TS3 Plus.

are you using the power supplied by the display to run your Mac?

The Mac is being powered by the MagSafe power adapter. I switched to this [from the display's power] while troubleshooting, but it appears to not change the behavior whether the Mac is receiving power from the display or a separate adapter.

I'm having similar, but not the same issues. I have an LG 5k Ultrafine and it works erratically with the MBP M1 max I just got. I have to reboot the Mac, plug it into the montitor using the TB3 cable that came with the monitor, and then close the lid of the laptop and use as normal. If I just plug it in, or leave the laptop open the monitor turns off and anythign connected through the hub in the monitor won't work (logitech keyboard and mouse). The same monitor worked flawlessly with my previous MacBook Air M1.

There must be something with the new M1 max that is causing this.

Yes. The article has not been updated yet because technically, it is not released until Tuesday.

Is this display a ThunderBolt Display or DisplayPort display?

How are you making the connection to the display? mention every adapter, dock, and cable.

EXACTLY what happens when you use any of these adapter or cables?