Macs running Mojave freeze when connected to the Internet

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Macs running Mojave freeze when connected to the Internet

I have had this strange problem suddenly appearing on the MBP : Within Mojave, some of the apps freeze for 7 secs at every mouse click (launching, moving windows). I have installed a new system on the MBP but migrated my old preferences. No change. Then I noticed that my Mini 2018 with Mojave behaves exactly the same. That happens on Ethernet and well as on Wifi. The apps launch instantaneously and work flawlessly when I am not connected, but as soon as I plug the Ethernet cable or activate Wifi, everything slows down drastically.

All was working well for years, and suddenly, not any more. I had done a search for a tracking number in Google, and then clicked on the link to a tracking website that was provided. That tracking website could have been fake, since it cascaded to another and provided no info. But the window froze, and since then I have had this problem. I tried the old iMac with 10.6.8, connected to same network, and there is no problem at all. Same with an old Macbook in Yosemite: no problem. The problem seems to be limited to the two computers running Mojave 10.14.6, both with a no battery wireless mouse. Since I did not browse the same websites with both, I wonder… Could the router have been infected? (provided by the cable company).

I ran Malwarebyte on my MBP and it reported no security threat.

I'm stuck now on what to do and how to investigate further. If this situation rings bells for someone, would you please share some hints?

MacBook Pro Retina

Posted on Sep 19, 2020 3:33 AM

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Answer 1

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alpshiker Author

Level 2

461 points

Sep 19, 2020 7:23 AM in response to alpshiker

It seems that the blockage was solved this way:

I had tried the suggested elsewhere trick: network settings => advanced => IPv6 => Manual instead of Automatic (off is not available in Mojave). Changing this had not solved the freezes. But after restarting the MBP, and setting IPv6 back from Manual to Automatic: Bang ! It works normally again ! So this is kind of strange issue, but at least it is fixed for now. Might have to do it for all configured networks (Ethernet and Wifi).

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Answer 2

alpshiker Author

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461 points

Sep 19, 2020 4:09 AM in response to Matti Haveri

Matti Haveri wrote:

Have you tried another network? For example, use a cell phone's Wi-Fi hotspot. Check or reset the network settings (AFAIR MTU defaults to 1500 etc).

No, but that's a good idea. I'll try this out when I can.

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Answer 3

alpshiker Author

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461 points

Sep 19, 2020 7:49 AM in response to alpshiker

WAIT … There is one caveat though : I could not reproduce this procedure on the Mini 2018 with the same results. It is still affected with the problem. But at least the source of the problem is more targeted.

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Answer 4

Sep 19, 2020 10:14 AM in response to alpshiker

My normal troubleshooting voodoo:

Remove all nonessential peripherals, reboot the net server if possible, reset SMC and PRAM, safe-boot, boot into Recovery mode, check Disk First Aid and check if the error persists.

If that fails, log in another user account and check if the error persists.

If that fails, clean install on an external drive and check if the error persists.

If that fails, check for any memory or other hardware failure...

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Answer 5

BDAqua

Level 10

245,585 points

Sep 19, 2020 10:15 AM in response to alpshiker

Make a New Location, Using network locations in Mac OS X ...

System Preferences>Network, top of window>Locations>Edit Locations, little plus icon, give it a name.

System Preferences>Network, click on the little gear at the bottom next to the + & - icons, (unlock lock first if locked), choose Set Service Order.

The interface that connects to the Internet should be dragged to the top of the list.

Sys Prefs>Network>highlight the Interface you're using>Advanced>TCP/IP>Configure IPv4: Using DHCP.

If using Wifi, instead of joining your Network from the list, click the WiFi icon at the top, and click join other network. Fill in everything as needed.

System Preferences>Network>choose interface>Advanced>Proxies Tab, make sure none are set, like for HTTP & HTTPS.

System Preferences>Network, unlock the lock if need be, highlight the Interface you use to connect to Internet, click on the advanced button, click on the DNS tab, click on the little plus icon, then add these numbers...

8.8.8.8

8.8.4.4

1.1.1.1

9.9.9.9

Apply.

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Answer 6

BDAqua

Level 10

245,585 points

Sep 19, 2020 2:10 PM in response to alpshiker

Well, a New Location covers a dozen or more files that could be a problem, I suspect it was it was simply DNS or lack of.

DNS Servers are a bit like Phone books where you look up a name and it gives you the phone number, in our case, you put in google.com and it comes back with 216.58.194.206 behind the scenes. :)

In a browser's URL bar, put this & hit enter, does that get you to google.com?

216.58.194.206

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Answer 7

alpshiker Author

Level 2

461 points

Sep 19, 2020 7:29 PM in response to BDAqua

It does lead to Google, yes. After getting the networking to be back on track with your manual settings, I reverted to the Automatic location, by renewing the DHCP settings. And it works fine now, even though just renewing DHCP had not solved the problem prior to making a new location. Perhaps, some file needed be overwritten or deleted. What puzzles me though is that both computers experimented the same problem at the same time. Maybe what initiated the failure was an update in the remote DNS server? Or some kind of malignant attack caused the server to partially block my access? Anyway, thanks to your targeted hint, I could implement the workaround before getting desperate and throwing it all through the window (LOL).

I went too fast when I tagged the IPv6 procedure as the correct answer and can't tag yours instead. But many thanks for your steadfast assistance and efficient help!

Have a nice day, Paul

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