Big Sur logs out when connecting an external display

After more than a month here is my experience with the issue #2.

1. It happens absolutely randomly: whether the external monitor is connected or not, or I put the MBA to sleep, or I closed the screen, or it just sits there staying idle.
2. It can happen after a night, a couple of hours, or just half an hour.
3. The culprit is obviously Big Sur because it can be any application:

I would be just slightly annoying if it weren't for LibreOffice because it does close the documents that are saved. So I found a trick: after saving a document, I add just a small change (a space) to make it unsaved. But I work on long and complex reports so I open several windows to be able to edit different sections simultaneously. When LibreOffice is ordered to quit it starts closing the windows in descending order until the first. So I can stop it but it has already closed all windows but one. I have to reopen them and find out where I was in my editing.

It's very annoying. I makes the look and feel unreliable.

Nick

My configuration:

MBA M1

RAM: 16GB

SSD: 512

Dock: AWC Thunderbolt 3

Hi Steve, thanks for your input.

Here is my setup:

1 - MBA M1 with Mac OS 11.2.3

2 - Dock: OWC Thunderbolt 3.

OWC, like Belkin and other vendors, thrives on the market opened by Apple with the Malthusian policy of putting two TB3 ports only on MBs. While most PC laptops have a collection of different ports (USB A and C, RJ45, etc.) and a card reader, most MB users need a hub or a dock and there are plently of them. OWC is one of the high end makers that target specifically the MB market. I tend to trust their quality and the compatibility of their products with Macs. Failing to do so would be shooting their own foot.

It works on TB3 only. I tested it on PC with a USB C connection: only the RJ45 was working.

1.1. - TB3 connection MBA <-> Dock

Since the original cable is way too short I bought a longer one (~3ft):

NIMASO Cable Thunderbolt 3 1M 100W 5A/20V 40 Gbps Thunderbolt 3 USB C, braided Nylon for MacbookPro iMac, iMac Pro, etc.

It's rather expensive and seems to be a rather high-end product.

As a test I installed the original cable again.

1.2. - Peripherals on the dock:

1.2.1. - 1 USB A HD. Not new.

1.2.2. - 1 USB A SSD. Not new.

1.2.3. - 1 USB C SSD. Not new.

1.2.4. - 1 optical S/PDIF cable to a DAC (connected to an amplifier). Toslink is a one-way connection so it can't mess with anything upstream.

1.2.5 RJ45 Ethernet cable to the LAN switch/ WAN router.

3 - KVM:

Tendak DP 8K KVM 2x1 switch DisplayPort USB 2 Ports

A rather expensive, high-end device. I don't know if it has a firmware and if so if it's ugradable. It's plug and play and requires no driver. Works on Macs and PCs and in a mixed environment. It has a separate power supply so it's not powered by the USB cables.

2.1. - Video connection cable to the Dock: a new CABLEDECONN Mini DP to DisplayPort 8K 8K (7680x4320) @ 60Hz 4K @ 144Hz DisplayPort 1.4

2.2. - USB connection cable to the Dock: an ordinary used one.

2.3. - An Apple wired keyboard. Not new.

2.4. - A Logitech mouse. Not new.

4 - Mac Mini late 2012 with Mac OS 10.9.5

I keep this old fashioned setup because I still need some legacy softs that either are discontinued or I don't plan to upgrade. It's a handy backup too. Has worked for almost a decade without a glitch even though some years ago it fell from my desk on the floor while it was running.

It's connected to the KVM the same way.

5 - External monitor:

HP Pavilion QHD 32" (USB Type-C/USB 3.0. 2 560 x 1 440. 16:9. 60 Hz. 20 Ms)

Bought late 2019. Worked without a glitch since then whether with a Mac or a PC.

Quality of operations

All this stuff are either not new and never failed or new and rather high end.

All connections through the dock are nominal. I use simultaneously many of them:

1. - The display on the monitor is perfect and constant whether with the Mini or the MBA.
2. - KB and mouse work seamlessly.
3. - I often use the USB C SSD for photo editing.

4. - Music is constantly playing without a glitch: Toskling requires a perfectly stable transfer rate, the DAC has no buffer and I doubt the dock has one. The only buffering device is the computer. I never heard an interruption or a change in the rate.

5. - Internet connection is perfect and very fast (I have an optical fiber Internet link).

All these data are transfered via the TB3 cable which obviously does a good job.

Some years ago I had a USB HD that had a faulty connection and would make the Mac crash. Everything was sent down the drain and the Mac would start up again. In the current case it's not a crash, it's an orderly shutting down of the MBA with Big Sur first odering applications to quit, each one obediently proceeding to close the open documents and gently asking the user if s/he wants to save them. It's the regular procedure. The question is: who gave the original order? I don't see how any of the connected devices could send the message: "Shut down". It doesn't look like a failure either. It looks like a system error.

Should I do clean re-install? I never did that. I don't how to do it and if it's relevant.

Nick

I tested some more configurations. The last one:

• I disconnected the dock so nothing was plugged to the MBA.
• I plugged in the charger.
• In the System Preferences > Battery I set the Turn the display off after: option to Never to make sure the MBA wouldn't fall asleep.

Since the event happened when I came back exactly one hour later I could tell the time it took.

Conclusion: it's the System.

Nick

Thanks for your quick answer

About issue #2.

Since it's random it's difficult to determine the conditions that make it happen. Yet I noticed it seems to happen only with LibreOffice and only when it's in the forefront. It reminds me that with my Mini there was a similar issue: when putting it to sleep I used to switch off the monitor too. After waking it up LibreOffice used to remain frozen for at least 5 minutes: if it was in the forefront there was no way to do anything with it and if it was in the background it wouldn't come to the forefront. No other application had the issue. Then I accidentally noticed that, unlike what I thought, it was not because of the Mini being in sleep mode, it was because of the monitor being switched off. Strange, isn't it? So I would just put the Mini to sleep and it was fine.

So the issue #2 seems to actually concern LibreOffice and not Big Sur.

About issue #3.

Thanks for the tips. When I have more time I'll thoroughly study it.

Nick

Hi Steve

Here my experience after a few days:

1 - I removed the after market TB3 cable connecting the Dock and plugged the cable that was bundled with it. At one point I was busy doing something else and the event happened after about half an hour. So the cable seems innocent. The MBA was not completely idle since it was playing music.

AFAIK, TB3 have a chip in their connectors which is probably why they are so expensive. So I was wondering if this chip might be responsible for sending signals leading to a log-out.

2 - Before closing the MBA for the night I ejected the volumes and disconnected the TB3 cable. The next morning nothing had happened. Since the logging-out is extremely random no conclusion can be drawn.

3 - I upgraded OS X to 11.3.1 and since then nothing has happened either.

Let's hope for the best. :-)

Nick