How to resolve flickering and unusable external monitors with the new MacBook Pro 16"? Displays have worked with previous MacBook Pros.

I have the same problem (ethernet) with WD15 (mine is 2018 air, 10.15.2). The only solution now is to reboot the mac. It only the first time you connect the device. Once you disconnect it, you have to reboot it no matter what. (you can try to switch off/on. ) I guess catalina is the problem.

when you turn off the ethernet and turn it on again, it somehow works but very very slow.

(you can try yourself "sudo ifconfig XXX down/up", XXX is id of your device)

I have this issue with multiple setups; I run an IOGEAR dock that pushes 100 Watts and I still have this issue. I have an ASUS portable monitor that worked fine on my MacBook 2016 without issue but new MacBook Pro 16 inch can't run it. There is a driver issue. Ive also noticed that when I use the Apple USB-C dongle my MacBook Pro stops charging when it goes to sleep.

I'm seeing a similar behavior.

It usually works. But I had this issue twice today. Usually I'm waking the computer from sleep. The screen on the MBP repeatedly flashes, and nothing happens on the external 4k dell display.

Restarts always seem to fix it (this is not an acceptable solution). I also just tried plugging it into the right hand side USBC port and it worked just fine. Not sure what's up with that. I'm using the CalDigit USB-C pro dock, with display-port. As it's working for now, I'm going to leave it and get back to work, but I don't have a lot of confidence in this solution always working.

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Macbook Pro 16"

2.4 GHz 8-Core Intel Core i9

64 GB 2667 MHz DDR4

AMD Radeon Pro 5500M 8 GB

Intel UHD Graphics 630 1536 MB

Andystrandquist wrote

:... Also, it stopped charging as well after going to sleep.

If you are charging with an external dock rather than the Apple power adapter, it probably sent a "go to sleep" signal to the dock when it went to sleep. Use the Apple Power adapter for best results.

If you are using HDMI, which was invented for HD TV sets, it is being stretched to the breaking point by hi resolution displays. There is more than little black magic getting HDMI to work at higher than HD resolutions -- everything must be perfect, and the cables must be exceptional.

If your display has a DisplayPort family input, using that would be superior and far less trouble.

Indeed, I tried a thunderbolt cable and mini display port from thunderbolt with the same issue. This is a hardware software issue. I had no issue with my other Mac. This is a MacBook 2019 16 inch issue. All varieties have issues.

Many, many other users are connecting a multitude of displays and using them without the complaint of flickering. [Fan Noise they complain about, but not flickering.]

You should contact Apple Support and arrange to have your MacBook Pro setup evaluated. Take all your gear to your free appointment at an Apple store. You can start with the "Contact Support" link at the top of every forum page.

plkris--

When eliminating the dock eliminates the issue, What you are saying is that you don't have a MacBook Pro problem, you have a DOCK problem.

There are many different approaches taken by the many different Docks. Some use DisplayLink technology, and are having a hard time right now.

The hub/monitor/MacBook 16” combo works fine when you first hook it up. It’s after the MacBook sleeps overnight that the flicker/display initialization loop starts when you wake it. It’s happened the last two mornings in a row. On the other hand the 15” didn’t do this once over years of use.

@rtgtrovador

Did you every find a fix for this? I'm having the identical issue. I'm using the same Dell WD15 hub. Worked fine with my 15" MBP, now the External monitor flickers with the 16". I guess it's hold my breath for a patch or upgrade to a different hub, at which point I'll probably start looking at another monitor solution.

Having a similar issue with an external display (LG UltraFine 5K Display) where sometimes the MacBook Pro doesn't recognize that it has the display connected to it. This is usually when it wakes from an extended sleep. I have to restart the MacBook Pro, disconnecting and reconnecting the cable doesn't seem to help. It is connected via the Thunderbolt 3 cable that came with the display (uses one cable to charge and feed video). I have the display set as my primary display with menu and the MacBook Pro is the secondary display. Prior to this display I had the original Apple Thunderbolt Display that I connected with an adapter. Same thing was happening, so I thought it was the display and adapter, which is why I purchased the new display. Anyone else have this issue or a solution?

I started with the LG-supplied Thunderbolt 3 cable and switched to the Apple Thunderbolt 3 cable. The not-waking-from-sleep issue is happening regardless of which cable is being used. And it happens whether the LG monitor is supplying power or the Apple Power Supply. Many threads about the wake-from-sleep issue, so thinking it is not a cable issue. Hopefully fixed with a software or firmware update from Apple.