After update from 10.15.3 to 10.15.4 external displays doesn't work via docking station

Yelling & venting at Apple here isn’t going to help you. If your organization had its act together only one Mac would have been upgraded, and tested thoroughly before all the other Macs were upgraded. Call Apple support and the hub manufacturer and maybe try a good certified cable. Just sayin’

These types of comments are just as unhelpful, PhaqApple. Vut Apple should also not release faulty OS upgrades without first warning either third-party vendors so they can give ample time to warn customers or provide customers clear guidance of what's happening. Telling people there organizations suck is basically saying customer's shouldn't expect there products to work when they update them... I understand where you're coming from, but people have a right to be upset about this.

I'm facing the same issue, but it is not happening on my 2018 Mac Pro, 15 inch, with similar specs to my laptop that is not working, which is a 2019 Mac Pro 16 inch. The 2018 works with my adapter + HDMI running 10.15.4, but not the 2019. I've tried resetting the SMC and nothing happens. To me, it's just like the laptop doesn't even recognize that an external display is being plugged in at all, which is pretty frustrating.

[Edited by Moderator]

I saw your original comment via email. Name calling is not productive.

I’m not sure what you think isn’t helpful.

Apple releases beta versions of software in part so developers can test, report problems, and correct them if they need to. Apple can’t test or correct every instance and variation and combination of third party hardware and software, and they certainly can’t know this report it, or they wouldn’t get anything else done.

I’ve supported depts with Macs in the past. I’d never install anything on all of them without first checking for compatibility on one first.

Again, I’d encourage you to talk to Apple directly and also any third party. Your concerns here are expressed in ways that are quite complicated. I hear your concerns but it seems you’ve come here to complain and solutions will more easily come to you by calling. They’ll likely even put up with your fussing.

Glad to see that you still attack the individual, and stick up for the big company. And not sure what is considered name calling, but that was not intended.

For everyone else who is having issues, continue to post them here. That is what this forum is for. To notify Apple that there is an issue and receive direct feedback from them. Not for people who don't have these issues to troll the message boards to make arbitrary comments. ; ). This issue is still present, and we all hope Apple issues something OFFICIAL other than ensuring everyone had a dedicated IT department that can do it for them.

You’ll note your posting was moderated.

It it’s fine to post here but you should also consider advice. That’s the real reason for this forum. People helping people. We all vent a bit, but focus on solutions.

If you don’t have IT support, I would again caution you and your organization from upgrading anything widely. Try one machine first and be sure all mission critical functions work before upgrading other machines. And call for support. The issues mentioned here are not easily solved in a forum, beyond the advice already shared, and that apparently has worked for some.

I’ll offer one more suggestion, which you may not want to try. Erase, format and do a completely clean install. Do it on a bootable external if you don’t want to erase your internal. That said, what I’ve seen here is that using different interfaces, hubs, cables results in it working. This suggests to me that it may be a hardware issue, or third party software. Call Apple. Call the manufacturer. Complaing about Apple here isn’t going to solve your problem.

Best of luck.

I wanted to add a couple of new symptoms. If the MBP is closed and the monitor is connected it will power on and give me the log in screen for the encrypted HD on the external display. However, once it starts to load the OS the external screen will go black and not come on again. If I lift the lid on the MBP it will be at the desktop and act like the external monitor is on (extended desktop).

Also, when the CPU usage spikes the external monitor will go black, come back on, go black and then come back on.

All of this behavior is post 10.15.4 install.

For what it is worth the System Profiler shows both displays connected to the Radeon Pro 5300M on my 2019 16" MBP.

It also shows the chip set in the HP USB-C G5 Dock as Microchip Tech. But that could just be on the USB 3.1 and PD side of things.

And lastly, once I do get it working through various fidgeting (mostly plugin, unplug, plugin, unplug, plugin...until it works) if I put the laptop to Sleep rather than Shut Down it will reliably start the external monitor on wake. I have done this over a couple of days now. So, there is just some disconnect when the OS (drivers?) loads at start up. And the weird screen flicker at high loads.

I have also come to realize that the dock is no longer charging the battery. The System Profiler shows that the power supply is connected and delivering 75 Watts. But it will not show as charging. The 96W adapter from Apple works fine plugged in to another port. So, may be a USB-C PD negotiation problem post update.

Just wanted to add a few more details incase anyone at Apple is following. :-)

I think that was what solved it for me (MP), usb-c dongle by Apple (usb-c to (1xusb-c, HDMI, USB)), tried everything and just switching to (in my case) usb-c port closest to the lid-end solved it. Funny thing is, now the the original port I was using works as well, go figure....

I have Lenovo USB-C 6-in-1, HDMI to my LG 4k TV doesn't work correctly anymore (Picture isn't showing on the whole screen, no matter what resolution I choose. Worked just fine on 10.5.3), and apparently moving files from USB sticks somehow broke as well. It only transfers first 1-5 gigs and then just gets stuck, until I remove the stick.

EDIT: Display problem was corrected with SMC reset.

I have a 16 inch MacBook Pro. In the end I’ve just given up and bought the Apple equivalent.

i can confirm it works with the Apple USB c device and failed with my alogic USB c device. A real shame but I had to keep working.

Same issue MBP, monitor, and Anker USB-c to HDMI dongle are two weeks old. Everything worked fine prior to update to 10.15.4, Now no external monitor, I have reset SMC, NVRAM/PRAM and nothing seems to work. This is a real productivity killer

I also have the UP2414Q and a 16" MacBook Pro. I'm also experiencing the same issue, and an SMC reset does not resolve it.

Even on earlier versions, the connection between the 16" MacBook Pro and UP2414Q would be unreliable — sometimes requiring a system restart to get any video to display, but now it's completely broken.

The same for my MacBook Pro 16 "with an Icy Box DK-2403-C docking station. Before the update to 10.15.4, I was on version 10.15.3, the monitor on the docking station was still working and now everything is what I was still get to see: "No signal". No matter what you try: SMC, NVRAM/PRAM, reboot or different order when switching on or plugging in.

I hope the problem is quickly recognized and solved by Apple !!!

Please report this issue to Apple by calling to the support team(https://getsupport.apple.com/?caller=psp&PRKEYS=PL107).

This community isn't that helpful to escalate the issue to Apple.

Last week, I made a call to Apple and the staff requested to connect to my Mac to find the problem. With all the suggested instructions including resetting SMC, NVRAM, he concluded that he needed to report this issue to the relevant team. To do so, I needed to support him—by taking several photos of the monitor by showing that it's working fine with another mac and also running a couple of programs to collect logs on my Mac. I uploaded those to the website link which was in the email from the same staff. Overall, it took me more than 30 mins.

If people with similar problems report the same issue, Apple will eventually know that their recent update has some relevant issue. I think this could be one of the most effective ways to let them know/solve the problem.

My external display is working fine - I have a Plugable TB3 dock and the external display is connected by DisplayPort.

However charging isn't working anymore. I have tried both forms of SMC reset as well as PRAM both before and after a rollback to 10.15.3 with a Time Machine backup.

Nothing works. I suspect T2 or similar firmware was updated which then isn't rolled back with a time machine backup.

I had call with someone from AppleCare, we made some diagnostics with my MacBook 16" with 10.15.4 and MacBook Pro 13" 10.15.3 that is working fine.

So they know it is bug relating to last update. So I hope it will be fixed ASAP.