Help me troubleshoot a sporadic issue on my Mac that I can’t replicate

If you recognize what’s happening with my Mac in the description below, by all means, shout out the solution. But what I’m really here to ask is what your first steps would be to begin troubleshooting this issue.

The problem: I got a 2020 Intel MacBook Pro a few months ago. It’s running Catalina. It has some kind of interruption in internet/network activity that happens sometimes and that I never had on the old MBP it replaced (that was also running Catalina) and that I’ve never seen on the other four Macs running regularly in my home.

This happens intermittently. Sometimes I see it two or three times a week, and then sometimes I don’t see it happen for a couple of weeks.


  • All browsers hang. This is usually my first indication that the issue has kicked in. I’ll try to open a page in Safari. Safari’s progress bar will stall, and the browser will just sit there doing nothing. If I go over to Firefox or Brave and try to get to the same page, the same thing happens in those browsers. They just hang. My default Safari home page is a local file — a tiny HTML file that lives in my Documents folder. When this issue is happening and Safari is hanging, even when I click Safari’s Home button to try to return to that local page, it won’t budge.

  • Reeder’s margins shrink so that articles are displayed one character wide. Is this directly related? I don’t know. But it’s weird, and I know that I only see it when the browsers are hanging as described above. When I see a browser hang, I know I can launch Reeder and the text in Reeder articles will appear



  • If I do a shutdown or restart, all apps close, the menu and dock disappear, and then the desktop picture sits there, eventually with a spinning gear appearing, sometimes for several minutes before shutdown finally happens.

I don’t always have to restart. Sometimes the issue goes away. But even after it goes away, the next shutdown usually takes a while.

I’ve seen a few other weird behaviors that I suspect are related, such as Time Machine and SuperDuper failing on scheduled backups, but I can’t say for sure that they only happen in conjunction with the browsers hanging.

I contacted AppleCare and the guy told me to boot into safe mode and see if the problem returns. But the problem can sometimes disappear for a few weeks. So I feel like I’d just be in safe mode for the rest of my life.

Most steps I can think of are similar: I can try something and wait to see if it prevents the issue. But I’m not even sure I know when the issue is being prevented and when it’s just not in the mood to happen yet, if you know what I mean.

What first steps would you take to try to figure out what is happening?

As a first try I’d probably force-quit Reeder and, if that doesn’t do anything, force-quit Safari.

Are you able to cycle power on your router?
It seems lots of apps need to phone home for authorization now, and internet issues can play havoc with more than just browsers.

I know zip about Reeder, but wonder if it is not able to read a .css file it needs for page layout information?

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They both quit easily enough, so I don’t even need to force-quit them. Or are you saying that it could be helpful to force-quit them anyway, sort of like a hard quit rather than a soft quit? (I think I’ve had to do like a special extra quit with 1Password in the past after an upgrade.)

Interesting. That makes some sense. I can’t get to our fiber box, but there’s a switch between that and my Eero. I’ll try cycling power on the switch and the Eero. Couldn’t hurt.

No, I’d say if they both exited without complaining, and the problem persisted, the problem probably lies elsewhere.

The next thing I’d try would be to keep Activity Monitor running, and see if you can see some process that’s tying up the network and/or the CPU. You might also have Console running so you can monitor the logs (this won’t be easy, there’s typically lots of log output). If you have any logging capability in your router, turn that on too.

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Try an SMC reset? It handles all sorts of weird things.


If your Mac has a T2 chip, try this SMC reset method for machines with T2 chips.

Weird WiFi issues might be at play – check out these fixes. The simplest thing might be just to “forget” the WiFi network you are on, reboot, and rejoin that network.

And, make sure you are on the the right WiFi network. I’ve had issues when the Mac had grabbed my guest network on booting rather than the main network.

Try an NVRAM reset.

Deep in my heart, I knew all along that this was probably the only real answer. I did an SMC reset last night, but I’ll be trying to do this preemptively for the near future.

I haven’t seen the problem in a month, since doing the SMC reset, so I’m going to assume that solved the issue. Thanks, all.

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It happened again.

Should have kept my big mouth shut.

Same symptoms. Stalled web browsers, weird one-column text in Reeder. Another symptom I don’t think I shared before is that my external monitor very occasionally goes black. This problem spans the life of two monitors — an old Acer monitor I’ve had for years, and a new LG I just got in January.

Shutdown took a long time, and when the computer did finally shut down, the fans kicked in for about a quarter of a second at full speed and promptly shut off again. Then, instead of shutting down, the computer restarted on its own and showed a kernel panic message.

Did you save the panic log?

I did. Anything I should be looking for in particular?

I looked at @tonycraine’s kernel panic log but, unfortunately, I didn’t find anything definitive. I had kernel panics similar to this on Catalina (as others have described it, “probably my least favorite [recent] macOS version”) but they seem to be gone on Bg Sur. I think we need a “Snow Bg Sur” release.