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

Upgraded from 10.15.3 to 10.15.4 this morning and now my external BenQ GL2250 monitor connected via USB-C/HDMI states "No Cable Connected".

MacBook Pro, 2019

AMD Radeon Pro 5500M 4 GB

Intel UHD Graphics 630 1536 MB

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.

Of course I know who M. Dell is. He is irrelevant to this discussion. I have Acer and Onn monitors trying to connect to a 2019 Mac mini. Neither connects through my APPLE C-HDMI adapter since the update...and no I’m not going to hassle either company over Apple’s mistake.

PS They sent out a patch last night to try to address the issue. Apparently Apple isn’t blaming Dell either.

Macbook Pro 15” June 2018, Asus PG348, CalDigit TS3 Dock (displayport 1.4 2Meter Cable), Macally USB Mac Keyboard.

Had an entire Sunday session of zoom conference PG348 and Macally Keyboard works fine until just now. However, i did find it odd after the update to 10.15.4, monitor have to hard power off to when monitor wont display.

Switched to HDMi now connected to a USB-C hub from 3rd party.

Help!!!!!!!!!

My issue is similar. After updating, my LG 32UD99-W monitor (connected by USB-C) started lagging. Mouse stutters all the way across the screen as well as dragging windows but becomes completely smooth when dragging onto the MacBook itself or my second external monitor (Asus PB278Q) that is plugged in via HDMI on my HyperDrive Duo USB-C Hub.

HOWEVER, if I disconnect my external monitor that is connected to my HyperDrive Duo USB-C Hub via HDMI, then my LG 32UD99-W monitor that is connected via USB-C works perfectly fine and the stuttering goes away.

All of this worked perfectly fine prior to the update and I just updated last night.

So, if I understand from multiple posts, most third-party multi-port adapters do not work on the HDMI (or VGA too for me), after the Catalina 10.15.4 update/upgrade. I have ioGear USB-C docking station model GUD3C02 that has DVI, VGA, and HDMI. The HDMI and VGA worked just fine prior to the update. I can't try the DVI because I don't have a cable. I have a monitor with DVI at one location but only have HDMI at another location. But it sounds like a plain USB-C to HDMI adapter, like from Apple in particular, would still work? Unless and until somebody fixes this, is a straight USB-C to "video" adapter the only option? And, is it Apple's responsibility or did multiple third party docking station suppliers fail here?

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.

Same here, targus 410 (MFT not displaylink) stop render display after mac OS 10,15,4, Tried to install last MAC update, do not solve the issue.

Batterie charging do not go up more than 90% since the update. MACbook pro is new (3 month).

Was working fine with 10,15,3

Well the odd thing in my case is that when plugging in my second monitor via HDMI on the adapter, it messes up the monitor that is plugged into USB-C. Seems like the refresh rate drops significantly where the mouse glitches across the screen when moving it BUT the monitor that is plugged into the adaptor works fine. However, when disconnecting the monitor from the adaptor, my USB-C monitor goes back to normal and is smooth. Again, this all worked completely fine pre-upgrade to 10.15.4 so it is most definitely caused by the update to 10.15.4.

So honestly not sure if this is an adaptor issue, power issue, or something else entirely.

Yes, I get what you mean, it’s like running a 4K Ultra Resolution Setting game on a GTX 560 Ti. You get 5 fps, at best.

Already got mine fixed.

a) Did a SMC Reset. Follow the steps carefully. Important is all ports must be unplugged and done on the Macbook Keyboard. I did it twice to be safe.

b) Power off all your external devices, monitors, and hubs while keep it disconnected from MacBook

c) After SMC reset. Power on / connect the devices to the hub / docking station before you connect the MacBook to the dock/hub.

d) Power-on your MacBook and Login without connecting to the Dock yet (don’t need to connect the USB-C Apple Power Adapter to the MacBook). Go to System Preferences --> Security & Privacy

e) Plug in your MacBook to Dock. With luck you might see an update at Security & Privacy that requires your approval for these devices to be connected.

Good luck.

Do not need to perform the full SMC reset.

I only need to perform the following

a) Shut down Mac with T2 Chip, without the cables or power connected.

b) Press and Hold power for 10 second. & release

c) All devices connected to Docking Station working.

I am having a similar issue. Since updating to 10.14.4 my external monitor (Samsung SE650) is recognised but there are a variety of display problems such as flicking lines/strange shadows and so on. I connect via a USB-C to DisplayPort Cable that I bought on Amazon (not Moshi but seemed to work totally fine before the update).

I am reading a lot about 'display port' but I do not know what this is. Could installing this help in any way, or do I need to wait until this issue is resolved in the next update?

I have tried resetting the SMC, etc.

Thank you!

Bethany

Okay. Will report back. At the moment the screen still has what I think are called 'shadows' - darker lines around the windows. The screen worked perfectly before, and is brand new. Pretty frustrating!

Apple really has grudge on Dell.

Do this step by step.

a) Pre-requisites, have your devices unplugged and power-off. Avoid plugging it in, until you have done the “full SMC reset”, I did it twice, before I try only doing the partial step. Up till the 10 sec power button hold.

b) With the devices still unplugged. Login Mac.

c) Then power-on devices and plug them in with your Security & Privacy settings opened. Watch for anything that might pop up or appear asking for permission. worry it’s a bug on different types of devices / drives when you start to connect them one by one - gradually.

if all else fail, call Apple. :D

I'm having the same problem after the OSX update, and it seems I ave the latest ('fixed') version. I use an external Dell monitor that I normally just plug directly to my MacBook Pro (13 inch, 2018) via a USB-C cable. Since the update this morning it is very buggy - sometimes the external monitor appears, then disappears and the monitor goes to sleep, and / or the resolution on both the MacBook and external monitor start randomly changing. Very frustrating! Seems worse when closing the MacBook and just using the external monitor.