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

Has anyone found a solution that DOESN'T require Apple's proprietary chokehold on my wallet? I'm working on a MBP 16, hooked up to a Kensington SD4600P USB-C hub and everything worked like a dream UNTIL I updated to 10.15.4. Now, everything works on the hub EXCEPT my LG HDMI display. I really don't want to have to drop another $70 to get Apple's stupid adapter.

Also, I have done all the resets (NVRAM, SMC, PRAM, etc.), booted in safe mode, etc. I was even on the phone with a lovely apple support tech for over an hour, last week, but her conclusion was that it's my monitor (which it clearly isn't, as I'm able to hook an older machine up to it without any problem) and not the OS update.

Does anyone have any answers?!?!

I've been using Apple stuff for ever and spent hours with and w/o Apple support on trying to get my Onn monitor to work again using a C-HDMI adapter cable that worked fine prior to update. I felt the same way you did but ended up buying the adapter. My mini is still under warranty and it was clear that I wouldn't get additional support w/o taking a bite of the Apple.

I'm restoring my MacBook Air to see if it will get back to one of the older updates and see if I can get back on my dock! In the meantime using my PC from work but would much prefer to be on my MacBook! I will keep you updated.

Stumbled on a fix. Two thunderbolt interfaces on the MacBook Pro, one for power, the other for data. I swapped the power cable to the other thunderbolt port and the system healed! Shut down MBP, swapped the ports beach to how they were and Presto - it works again.

I JUST HEARD BACK FROM DISPLAY LINK! I'm doing this for D6000. Hopefully if you contact them also, they'll have an update for your Dock! Here's their response for the D6000:

We have verified that upgrading firmware in your docking station D6000 resolves this problem.

This upgrade can be unfortunately done only on a windows machine.

1. Download it from here: https://www.dell.com/support/home/uk/en/ukdhs1/drivers/driversdetails?driverid=t8y8t&oscode=wt64a&productcode=dell-universal-dock-d6000&lwp=rt 

2. Install it on a windows machine with a connected dock

3. Connect your dock back to your Macbook

It may be also requested to restart your computers so please follow the instructions within the D6000 upgrade.

Thank you for checking the above and letting me know if the issue has been resolved.

I am having exactly the same issue after update the software to catalina 10.15.4.

The MBP is just a month old and the external dongle is alogic one, also less than a month.

I tested the dongle with different laptop and the same monitor, everything works fine, but when use the dongle with the new MBP, never detect the monitor, always blank.

Now, I am unable to use external monitor for my work, and this has extremely affecting my productivity due to the COVID-19, and I have to work from home.

Hope apple can quickly come up with some update and fix this issue!!

For everyone here, the first rule before doing an update is to do a backup, so you can restore if anything goes wrong.

Now realize that just because several folks here are having a problem, that doesn’t mean the vast majority are, nor does it mean Apple messed up somehow. Apple releases beta to hardware and software developers before releasing to the general public, so the developers can test and report problems. If there are large numbers of problems the the release will get delayed. If there are a few unique problems, the developers will work to resolve those problems and hopefully have a fix ready when the update is released.

Apple can not possibly test every possible variation of hardware and software combinations. If developers don’t test their own stuff thoroughly, there is little Apple can do. If you buy the cheapest brand of hardware off eBay or Amazon, then don’t be surprised if things stop working.

Regardless, jumping to conclusions is not going to allow you to accurately evaluate your problem. As noted above and elsewhere, this could be a cable, hub and/or firmware issue that an update to the OS simply revealed.

This is all good, but you have to admit that when something works perfectly before an update, and then doesn't work after the update... the logical conclusion is that it's the update that is the issue. If it was a firmware issue, there would have been discrepancies before the update. No?

Anyway, I've tried a firmware update, but am not connected to my workstation at the moment. I'll test soon and see what happens.

Thanks for the feedback, everyone.

Thanks for your time and provide the help.

I trust Apple are doing a great job and do proper testing before they release an update. But remember they are releasing one update that for wide range of product across of few generation of hardwares across different regions, it is possible to make mistake, and it is ok to make mistake.

We report a problem is not blaming Apple on this, is trying to make things better, by giving more information, like what devices we are using, how we conduct the tests, and this will definately helping other users who are experiencing similar issues to fix the problem, and help Apple to rectify and conduct similar tests.

Also, on Apple's MacOs release note, they did say "Some features may not be available for all regions, or on all Apple devices."

Which this will explain why some user is having issues some are not.

Same issue! I updated to MacOS Catalina to 10.15.4 and my Dell D6000 docking station doesn't charge when connected to my macbook pro. I installed beta drivers for the D6000 but it didn't help. The only thing that seems to "work" is using D6000's USB and plugging it into an external adapter which has a USB-C. My laptop then begins to charge but does not mirror display or extend desktop on my monitor. This is bizarre since the D6000 has both a USB & USB-C extension. When I use D6000's USB-C solely it doesn't charge my laptop, however it does mirror display or extend desktop on my monitor.

Hi, I have a D6000 as well. When I attempt to upgrade using VMWare I get an error message asking that I use a USB plug. However, my macbook pro has only USB-C ports. I tried using an USB adapter with a USB-C port (i figured it wouldn't work) and it didn't work. I'm on a Macbook pro 2017. thanks

I got the same problem in my MBP 13''. In 10.15.3 all my two external display were working stably. But after upgrading to 10.15.4, one of the display totally can't be detected anymore, the other display sometimes working sometimes not working. How can I resolve this problem?

Unfortunately work wouldn't let me upgrade the Dock device. It must be done on a PC and I only have a Mac. PC asks for Admin password. Work is telling me in about 2 weeks they are getting more computers and I won't be able to use my Mac anymore. UHG.

The update didn't resolve the issues which I'm experiencing. My 27" Cinema Display still shows a blank screen (although its built-in USB-hub is working, so I am able to use the webcam and any connected USB-peripherals, which was also the case before applying the supplemental macOS-update).

I'd suggest it is an illogical conclusion to assume the OS update is to blame. More so because Apple releases software well in advance to developers. And if you are looking for solutions and not wasting time blaming simply, great. Let me share something from the manufacturer of my audio interface:

" On October 7, 2019, Apple released its latest version of MacOS: Catalina (also known as MacOS 10.15). As with all new operating systems, iConnectivity is conducting ongoing compatibility testing with Catalina."

Of course the point is operating systems change, and even those that don't cut corners may find incompatibilities, will certainly test for them and correct any the find. Apple may more fully adopt a standard or do something like stop supporting 32 bit, and any developer that doesn't want to be bothered to keep up, is screwing their customers. Yes, even a cheap cable that skirts the standards and works today, may not work tomorrow, when the demands might be a bit higher.

You bought a Mac; buy quality stuff to go with it. Avoid buying stuff because it is the cheapest on Ebay or Amazon.