MacBook Pro M1 restarts after disconnecting USB-C dongle

Hi all, so here is what I have done.

• I decided to use the genuine Apple VGA/USB-C multihub to exclude Anker 7 in 1 hub as a third party potential cause;
• I reset the SMC as per Nicholas_B2 suggestion but I was eventually able to replicate the issue;
• Next, I booted in Safe Mode
  • I was not able to replicate it by connecting an external hard disk via the hub and just opening a window in Finder looking at the external disk
  • I was able to replicate the spontaneous reboot by running a Carbon Copy Cloner back up, ejecting the external disc at the end, removing the hub and plugging in the charging cable;
  • I was also able to replicate the spontaneous reboot by opening a Photos library from the external disk connected via the hub and copying a small PDF to it and from it (I thought of this as a way to exclude that there is something about the Carbon Copy Cloner causing this)

I need to clarify that I'm trying all these things while the MacBook runs from the battery and when I unplug the hub I plug the charger and the cable (both came with the MacBook from Apple) to the same port on the MacBook.

It seems that the only thing left now, since I can replicate this at will even in the Safe Mode is to reinstall macOS which is a pain in the ...

Any other suggestions?

Ok, apologies for all of these posts but I just did things in the following order and it seems it might be the Carbon Copy Cloner (CCC) after all.

1. I reset the SMC
2. the MacBook runs only on battery
3. I connected the Apple USB-C VGA Multiport Adapter
4. Connected the WD Elements to the adapter
5. upon the disk loading in Finder I opened a few folders (no copying or moving file)
   1. Ejected the disk, unplugged the adapter, plugged in the power cable = no reboot
6. connected the adapter and the external disk and copied a PDF file to it and back from it to the MacBook
   1. Ejected the disk, unplugged the adapter, plugged in the power cable = no reboot
7. connected the adapter and the external disk and opened a Photos Library on the external disk, opened a photo, closed the Photos app
   1. Ejected the disk, unplugged the adapter, plugged in the power cable = no reboot
8. I connected the external disk via the adapter, ejected it and unplugged it the it was no longer showing in the Finder (but I could still hear the disk spinning). At the same time I opened the CCC but did not run it. Just opened and closed the software. Plugged in the power = reboot. 
9. To exclude the hard disk still spinning being the cause I plugged in hard disk via the adapter again, ejected it, waited for it to disappear from the Finder but while still hearing it spinning disconnected it. Reconnected the power cable = no reboot. In this case I did not open the CCC
10. Finally I did everything I did in point 12 above but did open the CCC before ejecting it (not running the back up, just opening the app and closing it) = reboot

It seems there is something about CCC that makes the MacBook reboot spontaneously.

Any ideas are welcome if you think I might have missed something

Hi Ryane77;

thank you for your reaction. I have the latest MacBook Pro with M1 chip running macOS 11.2.2. I can replicate the reboot by simply connecting either the Anker 7 in 1 hub or the Apple VGA/USB-C hub to one of the two ports, then connecting an external disc to the hub. I leave it there, do not do anything (no copying, no backups, nothing at all), I eject the external disk, remove the hub and reconnect power supply to one of the ports (I did all of the above just running the MacBook on a battery power). The MacBook reboots spontaneously in minutes after the power is reconnected.

This does not happen when the MacBook makes a Time Machine back up but that is done over Wifi.

I have read the instructions you sent but I already have the latest updates and there is no specific app crashing or causing the crash. It all seems to be connected to physically connecting the hub.

Hi Nicholas, thank you for the reply. I have reset the SMC as you suggested and for now, no matter what I do I cannot replicate the spontaneous reboot - so thank you. I will observe for he coming days and if it doesn't come back I will mark your post as a solution. Keeping the fingers crossed 🤞

Seems like I spoke too soon. Connecting external hard disk via the Apple VGA/USB-C dongle, ejecting the disk, disconnecting the dongle, reconnecting power and putting the computer in sleep, came back 10min later to a rebooted computer. Will have to try the Safe Mode now. Will report back.

To add to this post I was just able to replicate a reboot without CCC. Plugged in the external disc via Apple adapter, opened Photos library on the external disk. Closed it, ejected the disk, unplugged the adapter and plugged in the power cable. Rebooted within 1 minute after being put to sleep.

The reboot always happens when the computer goes to sleep, it does not reboot while I am working on it.

Thank you. Before I reinstall macOS does that mean a clean install where I will have to reinstall all the apps and fill in the logins from scratch (so, so called clean install) or is macOS capable of just reinstalling the operating system and keeping the rest intact?

Given that there is a lot of posts out there about M1 MacBooks bricking, rebooting etc. I just wanted to provide more info here. I have been in touch with the developer of CCC and here is what I was able to observe further.

what I experience is that the M1 MacBook Pro reboots when the external disk is connected via the Apple adapter without power delivery (not into the adapter nor into the other port on the MacBook). I run the back ups like this because of the reports of M1 Macs being bricked when power is supplied via an adapter (from Apple or other vendors even thought macOS 11.2.2. was supposed to prevent that) and also I sometimes use the Anker 7 in 1 hub to run CCC simultaneously to two external hard disks and it’s in a place where plugging the Mac in is cumbersome. 

What I find strange is that when I reset the SMC on the Mac and connect the external disk via the adapter, copy files to it manually or open a Photos library from it, upon ejecting the disk, disconnecting the adapter and plugging in the power supply it does not spontaneously reboot. But if I do the above and just open and close the CCC software without even running the back up it leads to the reboot within a minute of the MacBook going to sleep and subsequently doing the first scenario of just plugging in the external disk via the adapter, opening Photos library, ejecting, disconnecting adapter and plugging in the supply also results into reboot. 

It seems as if something in the process of CCC changes something which then leads to the reboots. I’m not attacking CCC just trying to describe what I’ve observed. 

Also, connecting the external disk via the adapter (Apple adapter in this case) and power delivery running through the adapter, running CCC back up, ejecting disk, disconnecting the adapter and plugging the power then directly into the MacBook’s port does not lead to the reboot.

So I have now even reinstalled macOS (11.2.2.) and I can still replicate the problem. I am currently in contact with CCC developer. If that fails I am calling Apple as I cannot have a €2000 machine rebooting at will under circumstances where I never experienced such behaviour on past Mac (Intel). I am a happy Apple user since 2007. Thanks everyone for your help. If you can think of anything else let me know.

Hi baeberlives123; thank you. At this point I have done it all. Reset SMC, reinstalled macOS, erased the hard disk and did a clean reinstall. The only reason for me to connect an external drive for now is to do the Carbon Copy Cloner back up. Since that is the only time when I can now replicate the problem I uninstalled it for the time being and will observe the MacBook without running the back up. I will rely on Time machine for now for the backup.

I have been in touch with the CCC developer and he looked at it from all different angles but there seems to be an issue on Apple's side with USB connected devices. Below is a small part of the kernel panic log I have gotten close to 50 times now and sent to Apple. I also find more posts like this online.

panic(cpu 0 caller 0xfffffe001dce0088): Sleep transition timed out after 35 seconds while entering darkwake on way to sleep. Suspected bundle: com.apple.iokit.IOUSBHostFamily. Thread 0x4bd5.

Debugger message: panic

Memory ID: 0x6

OS release type: User

OS version: 20D80

Kernel version: Darwin Kernel Version 20.3.0: Thu Jan 21 00:06:51 PST 2021; root:xnu-7195.81.3~1/RELEASE_ARM64_T8101

Fileset Kernelcache UUID: F78A48EC84D7C3283E7C6C67D00889A7

Kernel UUID: 9FE8C0DA-8ED0-381C-9CEC-2A779F3E1503

iBoot version: iBoot-6723.81.1

secure boot?: YES

Paniclog version: 13