Macbook Pro 2018 Crash when connected to Ethernet (Via Dell WD19TB)

[_MacTech]

Hi Everyone,

I am having a peculiar issue with one of my MacBook Pro's that recently upgraded from Mojave to Catalina. We use Dell WD19 (outdated link removed) TB USB-C Docks for I/O accessibility on our MacBooks. Until upgrading I have seen no issues using the docking station. I can use every port that the dock has except for the Ethernet port. When the dock is plugged in the MacBook functions normally up until an ethernet cable is plugged into the dock (The Ethernet is connected to a network). When it is plugged in the macbook's cursor will freeze in place after a short number of seconds, then the fans will rev. ridiculously fast before the screen goes black and the machine reboots.

What is interesting is that a MacBook Pro 2019 (Out of box with Catalina installed) when put in the same situation does not have a single problem. However every Mac upgraded from Mojave has the problem.

I have updated both the macbook and the docking station to latest.

I checked the thunderbolt versions and found a conflict.

The newer macbooks are running thunderbolt firmware version 55.3 / Link controller firmware version 1.41.0
The 2018 upgraded to Catalina from Mojave are running thunderbolt version 47.4 / link firmware version 1.34.0

Perhaps updating this firmware will solve the problem? I do not know if this is possible.
I checked the 2018s for updates however apple reports there are none, they are on the latest MacOS 10.15.6

Current workaround is using the UGREEN 40873 adapter (9-in-1)

 

[chscag]

Welcome to our forums.

Do you have another USB-C dock you can try other than the Dell?

It is possible that the older Thunderbolt firmware version is causing the problem, however, if Apple does not have a firmware update that can be applied, there isn't anything you can do.

I looked up the adapter you stated that you're using as a work around. Seems like a rather expensive solution especially if you need one for each MacBook Pro you're running.

 

[_MacTech]

Welcome to our forums.

Do you have another USB-C dock you can try other than the Dell?

It is possible that the older Thunderbolt firmware version is causing the problem, however, if Apple does not have a firmware update that can be applied, there isn't anything you can do.

I looked up the adapter you stated that you're using as a work around. Seems like a rather expensive solution especially if you need one for each MacBook Pro you're running.

Thank you for your reply!

Unfortunately the only other USB-C dock I have for testing is the Dell WD15, I also have a Landing Zone LZ5015T However this is meant for macbooks with touchbar.

 

[_MacTech]

As an update I have not yet found a way to prevent this issue.