Problems with WiFi on macOS Big Sur

I've updated to Big Sur from Catalina and I'm having trouble when connecting to WiFi networks. At first no network appeared and now even though it has connected silently to my usual network, it is showing as no connected, but internet actually works.

Anyone having this kind of problems so far? I haven't seen anything related on the forums nor the release notes.
Answered by Developer Tools Engineer in 613924022
Could you please report this via https://feedbackassistant.apple.com and attach a sysdiagnose?
You can trigger a sysdiagnose by running sudo sysdiagnose from Terminal. Thank you!

It is unbelievable that this issue is more or less 1 year old! Apple is not doing anything to help their customers... Even not a single message saying they are working on it! One of the reasons of purchaising a Macbook, was related to the "excellent" support given by Apple, and now I'm feeling really disappointed. This was my first Macbook, and for sure my last one!

Hi everybody. Finally I brought my Macbook to work in stable conditions without a single drop. As I have an ASUS RT-AX88U, and this one is configured on WPA2/WPA3, and that none of my devices show any issues, I thought my macbook will have the same behavior. But I was wrong... By creating a guest network and configuring it to work ONLY on WPA2, I was able to make my computer work as before without a single drop. Could somebody make a trial and let me know if this is the real issue we all are facing? I hope it help you guys to push further and that Apple solve this issue asap! Honestly I was awaiting it on the OS 11.5.2!

Regards

Facing the similar issue

I have problems with my new Mac mini 2020, 8GB RAM. I installed Big Sur 11.6 and my WiFi is unreliable. At first I believe Safari was the problems, but I connected my ethernet and the Safari behavior disappeared.

I need a OS fix for the WiFi misfire.

--- Ruben Reyes

I'm having the same issue. I can connect to Wi-Fi but then after a few minutes I'm losing the Internet connection. Restarting Wi-Fi helps but only for a couple of minutes and then the Internet is down again. All other devices connected to the same network are fine. Tried all solutions I could find:

  • restart,
  • network connection settings (new location, manual setting, removing files, DNS, renew DHCP lease, auto proxy detection),
  • reset NVRAM and SMC,
  • safe boot,
  • removing all VPN apps,
  • disabling startup items.

Nothing worked.

macOS Big Sur version 11.6.1, MacBook Pro (Retina, 13-inch, Mid 2014), 2.6 GHz Dual-Core Intel Core i5, 16 GB 1600 MHz DDR3

Hi all, I was struggling with this for some time now and wanted to share what I learnt.

Problem: I have MBP late 2013 model 13 inch with 802.11ac wifi card installed. I know it is old but with all the ports (HDMI, SD card, audio jack) and older keyboard version Apple has gone back to in 2021/22. Bluetooth was working fine but not wifi. Wifi connected and dropped randomly. Sometimes would stay connected. Clicking on Apple logo> about this Mac > System Report > Wi-Fi, everything from 'interfaces:' would not be visible, meaning there is issue with AirportBrcmNIC kext (Apple logo> about this Mac > System Report > Extensions > AirportBrmcNIC) showing loaded: No; loadable: Yes.

DO NOT WASTE TIME ON THIS... Do not try wasting your time using SMC and PRAM reset as this does not solve the issue.

Going to Apple support: They said, if there is a hardware issue, they will charge 25% laptop cost and replace entire keyboard/modem part of the laptop. They were not ready to even check the software and said they would charge basic fees. This may be specific to a Apple support office, where they did not have experts.

My understanding The interface related file gets corrupted and may work on and off. If you can specifically update related files, that should solve the issue. If you are not an expert like me, try this...

Solution

  1. Just reinstalled the big Sur using Command+R after pressing the power button, and connect using a USB-ethernet adapter and ethernet cable for internet.

  2. I reset the network settings and that helped temporarily but wifi would drop and on restart may/may not connect. In the finder window, click on 'Go' then 'Go to folder' and copy this /Library/Preferences/SystemConfiguration

Copy all the files in another folder for backup. Be very careful what files you delete here as it can affect your network interface and you may stop seeing the Wi-Fi card altogether. They are generally loaded on the laptop everytime you reboot it in the order mentioned You can then delete all the below files and restart. It will ask for your password. If you cannot see the Wi-fi card after restarting, delete the below mentioned files and copy 1 to 4 in the System Configuration folder from your backup folder and restart.

  1. Settings.plist
  2. com.apple.eapolclient.plist
  3. com.apple.network.eapolclient.configuration.plist
  4. com.apple.AutoWake.plist
  • com.apple.airport.preferences.plist.backup
  • com.apple.airport.preferences.plist
  • com.apple.smb.server.plist
  • NetworkInterfaces.plist
  • preferences.plist
  • com.apple.wifi.message-tracer.plist
  • com.apple.accounts.exists.plist

I repeated the above step along with restarting the router and MBP in safe mode (press and hold Shift key for intel chip Macs). This trick allowed me to have stable enough wi-fi to start reinstalling Mac OS big Sur using Command+R.

  1. One last thing, try to have a unique name for your Wi-Fi and use WPA/WPA2 configuration, have only 1 connection saved in Network>Advanced, so your laptop is not trying to connect to multiple saved Wi-Fi connections, this may cause Wi-Fi to drop as well. This may be if you have 'wifiname' and 'wifiname_5GHz' names saved for 2G and 5G internet networks.

Other fixes of forgetting the Wi-Fi and reconnecting, adding DNS (8.8.8.8, 4.4.4.4., 8.8.4.4) and other information available online and in this thread are useful and you can try that if your issue is not more upstream.

Final thoughts: All in all, I am happy with Apple, almost a decade on and still quite sturdy. May just keep this old one for regular use after buying MBP 2022.

I have an enterprise network running on Cisco Wireless lan controller. Its upgraded to Wifi6 which is a rather big problem. Since upgrade to Wifi6, the newer Macs wont connect to WPA2 enterprise with username/password. On an open WIFI they connect fine. Older Macs connect fine to the network. because they negotiate an older connection type.

What i have found is, that MacOS and Linux (basically the same) cant agree on the band they want to use for 5 GHz network. The result is rather obscure as the operating system returns with a "wrong password or username". This is wrong. On my wireless router i dictated the frequency band to be used (thus no negotiation) and the machines connected flawlesslys to the network.

This workaround isnt usable for Cisco enterprise networks because of the manu AP's running different frequencies, as to not jam each other.

If you have a private router, find an available frequency specrum and fix your wireless to that band as a work around. I cant give you the solution for this as there is a ton of different routers out there.

On enterpise networks managed by a wireless lan controller we will need a driver and protocol stack, that can handle this envirenment properly.

Apple, please look into this.

Problems with WiFi on macOS Big Sur
 
 
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