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

MBP 16" and Dell P2720DC problems started after installing 10.15.4. Three symptoms so far:

• When waking up the computer from sleep with Dell hooked up with USB-C cable, the login screen opens but the computer freezes completely (A beachball cursor totally stuck) and needs a power button restart to recvover. This happens every time, not occasionally.
• Also the original Apple USB-C Digital AV Multiport adapter does not work anymore with the Display connected to through adapter via USB-C. No image anymore with this setup.
• One time the computer suddenly froze completely and shut itself down and failed to start. The battery had drained from 100% to 0% after the freeze and plugging it to power adapter it was able to startup and begin recharging.

I could live with the Apple adapter not working until we get the fix, but the sleep and wakeup not working is really annoying.

Anyone else experiencing similar problems while waking the computer up with external USB-C display?

I've tried to do all resets (NVRAM, PRAM, SVC) but nothing works.

Oh dear - mine was my fault. I had taken it all apart a few days before for boring reasons and it turns out there are two thunderbolt ports on the back but one of them is low power and one high. Guess which one I plugged in :(

User error. All fine now.

As I've mentioned before, resetting the SMC works for me too, but I have noticed another issue after update - when I plug in to my hub (to USB 3.0) additional device, like iPhone, the iPhone is charging, but the MacBook is not charging anymore. When I unplugging the iPhone, the Macbook starts charging again.

All of these issues looks like some limitation in voltage / current - I think that's why some of you had some limitations in resolution or frequency on external screens also.

same issue with my MBP 2019. working perfectly fine previously but no power to my docking after update. waited a long time to talk to Apple engineered, tried SCM and reinstalling catalina 10.15.4, none of them work. weird enough, tried put my dock upside down, it's powered up and working. but that's not solving the issue fundmentally, apple needs to get it fix asap

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.

Just an update after the supplemental update was installed. On multiple USB-C to HDMI cables once the Macbook Pro sleeps itself, I can not get it to wake up without opening the MacBook Pro. Also I have to agree that the passive aggressive posting that Apple can't be to blame, and it has to be everyone else's fault is ridiculous. We all had different technology from different makers that was working fine before 10.15.4 and now it isn't working. Don't just worship and drink the kool-aid.

A perfect example is the LG monitor Apple was selling as the replacement for the Apple Thunderbolt Display that is not working for one of the users. Also as other users have said, they are having issues with Apple's own USB-C to digital AV adapter.

The best thing we can all do is continue to report the issues to Apple's Feedback form as it continues with each version they release if the issue is still happening.

https://www.apple.com/feedback/macos.html

Y'all need to focus on sharing enough info then getting solutions in am organized manner, including reaching out to both Apple and the manufacturer. Surely some folks have AppleCare, so they'll talk to you without question. And if you make it a macOS issue, they will likely talk to you even if you don't have AppleCare.

Most of all, always backup before upgrading. Use TimeMachine with a relatively cheap and large external hard drive. And consider getting an external SSD that is as big or slightly bigger than you internal drive, and use SuperDuper of Carbon Copy Clone to make a quick bootable backup, in case anything goes wrong. Clone right before an upgrade. You can get this 500 GB SSD for under $100 elsewhere.

Why the links to Apple? Because I assume if Apple sells it, it is good stuff that works well their stuff. You don't have to buy it from them, but it's good to know Apple is selling it before buying.

After installing the 10.15.4 supplemental update from 8th of April my USB-C dock and attached screens work as before. Don't know if Apple made an update or if it's because of a system reset due to the update. Point is that it's now back to normal

Just to give everyone an update.

I've been experiencing same issue after upgrading to catalina 10.15.4 with my Alogic USB C adapter which this cost me $149 AUD. After 2 weeks of struggling with no solution, I went to buy an Apple USB-C to Digital AV Multiport Adapter for $99 AUD.

And now I am able to connect to my external monitor. I am very sure that the Alogic USB C adapter is working with PC, but stopped working with Mac after this update. I don't really know what to say about this Catalina update, I understand that it is no easy for them to roll an update to make all the hardware adapters to work with them, but isn't this is a problem other brand are facing.

In my personal opinion it is Apple again trying to do something different/innovative, and other accessories brands are fail to follow Apple. It seems like if you buying Apple you have to deal with this kind of things. In the end, we, consumers are the biggest losers in this processes.

Again, just my personal opinion.

After biting the bullet, and waiting for UPS to deliver, I dropped another $70 to get the Apple brand USB-C to HDMI/AV adapter and it works like a charm. I'm still really unhappy that this is what it took. But thankful that I can actually use my 32" LG monitor again. C'est la vie.

I am also on the latest Catalina update 10.15.4 (19E287) and this has not resolved my external display issue.

System Software Overview:

  System Version: macOS 10.15.4 (19E287)

  Kernel Version: Darwin 19.4.0

  Boot Volume: Macintosh HD

  Boot Mode: Normal

 Apple support helped me and after several approaches no success. Finally had to reinstall OS X, which seemed to work (took about 1.5 hours to do the reinstall but this went smoothly. The display was connected during the reinstall process, and early in the process I noticed that the display showed a light grey on the display (which to me means that something on the computer detected and affected the display). After the install completed the external display was properly mirrored and the display showed uptimes in the System Preferences/display applet - it hadn't before. Unfortunately, once I disconnected the Mini-Display to usb-c adapter and plugged int back in again things were back to the start, where the display was no longer detected - by the hardware nor by the software (display applet). I am going to disconnect and unplug everything, including the adapters needed for the Apple CinemaDisplay I am connecting to. Hope this helps somebody.

Hey smoothitaway,

Yeah I have the same issue, I can run it with USB-C to HDMI at 30hz but I NEED 60hz. On my monitor if I change it to SST(single stream transport) I can get displayport to work at 30hz, so I think you should have a displayport option as well to get 30hz on displayport, but of course we need 60hz...

I should have mentioned I'm running 10.15.1 still because I do not want to inherit any new issues. However I run an elgato3 dock with a Apple 27 inch and a LG 27inch 4k monitor. Apple only gets the 4k LG resolution correct when first connected. The 4k was shared with my home machine running win10 via a HDMI switch. However, MACos only gets and sets the correct parameters when the 4K is present at start up. If I try and switch it the MACos driver switch it to 1920x1080. If I look at AGCDiagnose its because the MACos gets the bandwidth of the channels incorrect and down grades the speed of the possible connection from HBR2 to HBR. A duplicate machine with 10.14.5 works perfectly and sets HBR2 every time irrespective. Unfortunately the EDID override will not fix this issue.

The easiest way is to try switchresx as it enables an easy path to setting the overrides refresh and resolution. If you can get it to work with that then you can manually install the override or purchase it.

https://www.madrau.com/