MBP 13 2020 won't recognize USB devices from TB dock after sleeping and connecting to the dock. After unplugging the dock MBP crashes and does SMC reset

11.1 fixed it for me on my 2020 Intel MBA. I could reproduce it consistently every time before that version, and now I can't make it fail. It just picks up and keeps on going.

This is with multiple bits of TB hardware, too: a TB3 dock and an old Apple TB monitor. Both of them work, whether direct to the machine or with the monitor behind the dock.

It was bad, but it's over. Try it.

11.1 finally seems to fix the problem. Phew!

Just for context: my setup is a MBP13" 2020 and an external LG Ultrafine 5k.

My primary use case is starting to work, connecting the LG without ever opening the MBP's lid and working with the LG 5k screen, KB and magic trackpad connected to its USB-C hub all day.

In the evening, I disconnect the LG (lid of the MBP still closed), and later may or may not open the lid to use the MBP away from the work desk. Before 11.1, next time I connected the MBP to the LG 5k, either external USB would be dead with screen ok, or the machine would crash entirely.

Over time I found that opening the lid before disconnecting the LG 5k also prevented the problem - that's the workaround I've been using the past 2 months to avoid a reboot each and every day.

Now with 11.1, just putting the (closed) MBP to sleep and disconnecting the LG works fine. I haven't tried "hot" disconnecting (w/o putting the MBP to sleep) yet.

Essentially, Big Sur 11.1 fixed the main problem (dead USB or crash on reconnecting external LG Ultrafine 5k) for me, too, and 11.2 has not brought back any problems, either :-)

However my sound output selection/AirPlay menu reveals that apparently disconnecting and re-connecting the LG still produces a "zombie" of the monitor's USB audio, see screenshot.

So while for all practical purposes 11.1 allows me to work normally with my LG and external USB devices connected to it, there still seem to be problems related to TB connected peripherals Apple should fix…

FIXED by upgrade from Catalina to Big Sur 11.2.1

The issues I had:

1. Intel crash, when plugging in Thunderbolt Apple Display, or when coming out of sleep having had plugged in the Thunderbolt Display whilst sleeping.
2. System not seeing in built hub in Apple Thunderbolt Display, would only work after a Shutdown/Restart

MacBook Pro (13-inch, 2020, Four Thunderbolt 3 ports) 2 GHz Quad-Core Intel Core i5

Apple Thunderbolt Display (TB2)

Apple Thunderbolt 2>3 adaptor

MacBook Pro (13-inch, 2020, Four Thunderbolt 3 ports)

2 GHz Quad-Core Intel Core i5

My hub is built into my Apple Thunderbolt display, but I had all the exact same problems. Been perfect since Big Sur.

I was on Catalina for ages until Ableton & UAD supported Big Sur. Pleasantly surprised once I upgraded.

Try turning off Powernap. I received this tip from the Reddit community Discord, and it worked for me so far. (2 days, no hanging or usb issues.)

System Preferences -> Energy Saver -> Battery -> Uncheck 'Enable Powernap'.

(not on screen right now, so I may be misremembering exact words)

My second display issue through the TS3 Plus is still not fixed though.

I now seem to have found a reliable way of avoiding a reboot: I put the MBP2020 into sleep mode when I leave my desk for a longer period (overnight for example) and wait until my USB devices indicate that they have been disconnected. I have a hub with an LED for each port that lights up when a device is connected. When I put the MBP into sleep mode, I wait until those lights go out on the hub, then I disconnect the laptop. Next morning, I reconnect everything and alas, the lights come back up and all my USB devices are connected again.

This is a suitable workaround for me and only slightly more inconvenient that my normal routine (moving my mouse pointer into one (active) corner which switches off the display.

Hope that helps a few of you guys until Apple finally fixes this once and for all...

I have managed to install MacOS Catalina 10.15.5 in a separate partition. Though the testing was limited I did manage with no issues to put Macbook (Pro 2020, 13") to sleep, disconnect Thunderbolt docks, have it sleep for 5 mins and when reconnecting it all worked fine. Tried with both docks I own (CalDigit TS3+ and I-tec).

Therefore issue is not HW fault but bug Apple introduced in 10.15.6 .

I am aware that 10.15.6 was supposed to fix issues with sleep/wakeup and crashing 16" Macbook Pros ... and there was another issue with USB keyboards/mouse not working on 10.15.5 .... it is too much effort to move all files/apps to 10.15.5 plus my employer manages the machine so update to 10.15.6 maybe automatically installed.

Net is - am too tired from testing for Apple and not knowing if they acknowledge the issue at all nor whether they plan to fix it.

They do have from quite a few of us Crashlogs (and i assume number of people who do have thunderbolt docks is probably in 1000s if not more but only 10 complained on this forum) so I hope they do.

FYI Big Sur Beta 4 has the same bug and it crashes the machine and loses the ports as well.

So net is - issue is not HW but Macos. Whether Apple will do anything about it - I don't know if anyone will answer that question ?

I had powernap disabled on battery the whole time, so that alone can not be the decisive factor. I now tried disabling it on AC as well, seems to reduce the frequency of the issue. Otho, I now did an updato to Big Sur Beta 5, and even with powernap enabled, I am unable to reproduce the error.

Did someone else upgrade to Beta 5?

In the end I really have to say it is a shame Apple ignores bugs for months, but is able to remove Apps from the Appstore in hours if they don't contribute to the enormous wealth this company already has. Definitely the first and last product from Apple for me.

I found a partial workaround. Your mileage may vary.

I have 2020 13" MBP with an Elgato Thunderbolt 3 Pro Dock and experience both the kernel panic (system crash) and non-working ports that many others have described.

After systematically testing with separate user accounts, I can now avoid the system crash, by changing a setting in System Preferences under Security & Privacy in the General tab. I had set it to require password "immediately" after sleep or screen saver begins. As far as I can tell, on my system, changing this setting to anything else, e.g., 5 seconds prevents the system from crashing. But I still have a problem getting the Ethernet port to connect when reconnecting the dock. This still requires a reboot.

I hope this might help others avoid system crashes.

I have a clue to an interesting "fix" (but it´s not yet thoroughly investigated or confirmed):

My MacBook Pro 2020 has 4 Thunderbolt Interfaces. It seems (from looking at the System Report List) that each pair of these is connected to an individual Hardware Driver ("Thunderbolt 1" and "Thunderbolt 2"). Hot connect/disconnect seems to make these somehow "stuck", specifically in case the MBP went to Stby for more than 5 Minutes (Tea Break) during disconnect.

I simply tried to reconnect using the "other pair" of Thunderbolt/USB-C connectors on my MBP: disconnect from right side plug, go to Stby, get a cup of tea, re-connect to a plug on the left side. And: no crash. All fine.

I tried a couple times. And I had no time to investigate further or try more often. But no crash using this method:

Re-connect on the opposite side of your Macbook you were connected to previously.

Weird, eh?

My suspicion: someone forgot to implement an Interface to a reset function that may be invoked in the Thunderbolt controllers. However, such a function seems to be executed in case a connector is connected for the 1st time. This function seems to run on both HW controllers at the same time. Even if triggered by the "other" plug or HW. So, the function is there - just the interface to actually call it from the OS is missing.

Too complicated? never mind. Apple will know what I´m writing about ...

I already tried these options (left and right TB3) extensively, didn't work more that 4-6 times, it will crash.

Based on extensive testing I have done, there are only two scenarios that work ok long term:

• Catalina 10.15.5
• Big Sur 11 Beta 10

It is unfortunate that Apple hasn't proactively fixed this, even after so many real cases.

I had the same problem, too. Needed to reboot before plugging in my eGPU and after I ejected my eGPU. So I ended up in rebooting daily.

After migrating to Big Sur the problem is gone for more than a week now.

I run a MBP2020 with 2x CalDigit TS3+ docks in different locations. Each dock has two external Dell monitors plus external webcam and other bits.

Since upgrading to Big Sur I've not had a single problem - I've been able to successfully sleep the machine, wake at the other location and plug in etc. The CalDigit dock utility is aware of the dock and the external screens and external camera etc. all work fine. I'm in the habit of unplugging from the dock first, then sleeping the machine - not sure if that makes a difference?

So for me, Big Sur has fixed the headache problem of Intel crash reboots etc. which is a massive relief. I'm sorry to hear people are still having issues, even after Big Sur? I like some of the improvements in Big Sur too.

The only problem I have left is the atrocious battery life which seems to be related to Microsoft OneDrive constantly enumerating files.

It's disappointing that Apple have been so silent on the issue :(