MacBook Pro 16 external display issues

For me exactly the same problems occur. Also with the Eizo display (@home) but also with HP display (@work).

The suggested solutions do not work.

Sometimes a reboot does works for a while.

This is really blocking me from working efficiently with the new mac.

I have the same issue. On wakeup many times, the external monitor does not work. Sometimes changing the port fixes the issue. Other times it does not. VERY VERY unproductive to have to restart everything I want to use my external monitor after waking up. Frustrating with a brand new 16. Apple needs to fix this!!!

I have two different issues

1) With Thunderbolt display and apple branded dongle: The external monitor won't wake from sleep without repeated connect/disconnect

2) With Dell U3415W ad IOGear USB Docking Station Model GUD3C03: The external monitor wakes up washed out (see pic) or repeatedly goes to sleep and wakes up.

(Original Post here: https://discussions.apple.com/thread/250998764)

I've tried to contact support but they really don't want to do anything online. Guess I have to make a phone call. How 2002 of you, Apple.

Another issue: When I have my thunderbolt display attached and I go into Time Machine, scroll back a few days, and then click cancel, the dock moves from the Thunderbolt (primary) to my laptop screen. Happens every time. Something is wonky with how Catalina is detecting monitors.

When I called I was escalated to some "special" support and the guy was actually very helpful. We repro'd the problem and he got some logs and opened a case. That was 02/28/2020. Nothing has come of it yet, but I sense they are aware that this is a serious issue. In the meantime, it's driving me nuts and I regret "upgrading" to this new machine. Apple's software QA has gotten so bad that I rarely take a major OS update immediately anymore. Hardware seems to be the in the same boat.

Why do I have difficulty with Wi-Fi or Bluetooth devices when USB 3 devices are attached to my computer?

Some USB 3 devices can generate radio frequency interference that can cause Wi-Fi and Bluetooth devices operating in the 2.4GHz band to have issues communicating with your computer. Here are some tips to avoid this issue:

• If your USB device has a cable long enough that you can move the device, place it away from your Mac—and make sure not to place it behind your Mac, or near the hinge of its display. The antennas for Wi-Fi and Bluetooth are located there, and USB 3 devices placed there might interfere with your wireless connections.

• If you're using adapters or dongles on a Mac computer with Thunderbolt 3 (USB-C) ports, plug them into the front port on the left side of your Mac, or into the ports on the right side (if your computer has them). These ports are the farthest away from the antennas, making interference less likely.

• To avoid interference on the 2.4GHz band using Wi-Fi, try using the 5GHz band instead. You can change this on your wireless base station. Bluetooth always uses 2.4GHz, so this alternative isn't available for Bluetooth.

from:

Using USB devices with your Mac - Apple Support

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I appreciate the reply but it is NOT just RF interference. When my machine starts having problems with detecting monitors the Display prefs get hammered (lose color profile, True Tone won't switch on or off, etc.). The next escalation is the system won't boot until I unplug the external monitor. The next escalation is a black-screen and after I hard reboot all my Notification Center widgets are out of order. Something is getting very confused in the OS.

I at first thought moving the HDMI connector, and getting a mega-shielded cable, had fixed things. And it did fixed the external monitor shutting off intermitently. But this other stuff still happens. It takes a couple days before things start going sideways, but the more often I sleep/wake the machine, the more likely it happens.

I plan to call into Apple Tech Supt again next week to register my findings on this. Something is definitely wrong and it's clearly affecting a lot of people.

<<Feigning ignorance of a problem is SOP for Apple. >>

That is unfair. The people you asked are generally "first responders". They are selected for their ability to be nice to you, follow the posted procedures, find applicable articles, and coach you toward resolution without screaming at you.

What they do not universally have is deep expertise on EVERY issue (and "First Responders" are NOT specialists -- their next call may be about the iPhone, after that earbuds, then speakers).

It is not surprising if they do not connect the dots, and that is not their job.

That is more the job of second-level experts. They may (or may not) have seen enough of your exact issue to connect your symptoms to what they heard on previous calls.

Apple Engineering only Acts on Bug Reports, and returned and failed computers. Apple Engineering does not act on AppleCare calls unless they result in filing a Bug Report. It does not act on Genius Bar visits unless parts are replaced or the computer is returned.

I’m having this same issue with my 16 latest Catalina . I even bought a apple hdmi adapter to see if that would Mitigate the issue. It worked fine the first few days now my displays are going in and out again. Help!

Thank you, but no :-) One port per display (same configuration that worked for years with Macbook Pro Retina 15").

By the way I was forgetting, some days (like today) I just find the mac restarted due to "Panic: Sleep transition timed out after 180 seconds while entering darkwake on way to sleep." (obviously I send the report)

I’m having the exact same issue with my Eizo and MBP 16inch. It crashes the computer when it goes to sleep. In addition to this, I can’t only get 30hz refresh rate on the display, and only some connections work.

Resetting the NVRAM/PRAM, SMC didn't help. I have tried on Safe mode/safe boot too, and it's the same.

i have the same issue. Tried everything this thread mentioned and nothing worked. My old Mac works fine with all of the hdmi adapters I have. New one doesn’t, which is really disappointing.