10.13 High Sierra Wi-fi issue

same here, no issue with Sierra on my MBP Retina 15-inc (Mid 2015). Seems like only High Sierra my MBP is not connecting to the 5Ghz. Have no issue with connecting to the 2.4Ghz but not 5Ghz.

I would say there is a bug in the OS.

I can't reset cause that's blocked by the ISP, I can login to the router but all those settings are locked. On hardware reset the ISP gives it back the SSID name that is known with them and i'm not allowed to change the name and password.

2.4Ghz test:

Did iMac to sleep mode, waited few minutes, braught it back (wake) and logged in. CPU usage goes through the roof (kernel_task 100% in activity monitor, see usage graph below during that time and after it reconnects), you notice the slowness when moving the mouse gets bumpy. After a minute, the connected wifi drops out, iMac tries to reconnect and that takes a few minutes and then reconnects again. The CPU usage then comes to a more normal level (as the image clearly shows).

I had the same problem with my Mac Mini. For whatever reason the WiFi option was not detected by my Mac. Inexplicably everything suddenly started working again after 2 days with no access to the internet. I was sent a link to report the problem as feedback for Apple. Here is the link if anyone else wants to give feedback.

Product Feedback - Apple

5Ghz: Dragging it to the top should help you even adding back other networks.

DO NOT HIDE the network.

Router should be configured to 802.11a/n & if thats causing issues then try just the 'n'

Click Advanced and go to DNS settings and make sure Googles two are on top: 8.8.8.8 & 8.8.4.4

You may need to set manual MTU to 1453

20 or ""40 MHz

"You may need to change your 5Ghz channel from AUTO to 40, 41, 44 or 48; as an alternative.

Check if you don't know your current channel from wifi icon by holding OPTION while clicking.

Recommended settings for Wi-Fi routers and access points - Apple Support

another easy way to auto start this script is as follows

You can:

• start Automator.app
• Select "Application"
• click "Show library" in the toolbar (if hidden)
• Add "add apple Script" (from the Actions/Utilities)
• Copy&paste your script into the window
• Test it
• Save somewhere, for example you can make an "Applications" folder in your HOME (you will get an your_name.app)

  Update: For latest macOS, name your file

  your_name.command

  instead of

  your_name.app

• Go to System Preferences -> Accounts -> Login items
• Add this app
• test & done 😉

The have the same issue on a late 2009 iMac update from Sierra to High Sierra. I've manualy deleted the Wi-Fi and network configuration files, create a location ... After a lot of test I have found your solution and it has worked to me.

I also own a late 2013 MacBook Pro which I have updated from Sierra to High Sierra with no Wi-Fi issues.

Then this might be an iMac issue or for older Apple computers.

Thank you for posting your solution it has been helpful to solve my iMac Wi-Fi issue.

Sergi

Downgraded my MBP 13 (Late 2016) back to OSX 10.12.6 sierra but this doesn't help anymore.

I now also have trouble connecting using OSX10.12.6 Sierra, looks like this also applies to de USB-Lan adapter

My MBP Retina (Mid2012) still runs flawless on OSX 10.12.6 Sierra, I don't dare to upgrade it

My wifi broadcasts 2.4Ghz but I will try to change it to 5Ghz tonight, who knows maybe it will help

Having the same issue with a 2015 27” iMac, keeps dropping the connection, will not connect etc. 2 laptops, along with numerous iPads etc all connect to the WiFi with no issues. Using High Sierra public release along with beta 1. All of the Public Beta releases of High Sierra worked fine

My ISP has checked everything and the router does not appear to be at fault, have had to resort to wired connection.....

Clean Install High Sierra 10.13.0 on late 2012 iMac without any issues. Computer will auto connect to 5 Ghz wifi after idle and after wake from sleep but am getting Broadcom Driver crashing at least twice since the clean install Oct 1. Reading the crash logs something about power stat =0 that correspond to time of waking from sleep.

Have had similar issues as this one on Retina MacBook only happening on Sierra 10.12.6

No solution for either machine except to kill wifi altogether when certain not needed for extending period of time or in Terminal run caffeinate -i.

Found a solution.

Same issues that everyone here is reporting.

I am on ATT giggabit.

ATT had me update the SSID from the default SSID and that instantly fixed all of the connections issues.

Try updating your SSID and PW in your router settings. Or you can contact your net provider to do it for you.

I have fixed this issue in early-2015 Macbook Pro by changing the host name (SSID) of my Wifi Repeater/Extender. Before this, my Macbook randomly on & off wifi or sometimes won't connected at all, and I had Wifi Router and Repeater with a same host name. I hope this help. 🙂

Similar problem here on iMac 27" (mid2010). Vintage, but still performing i7-16GB machine.

WiFi doesn't automatically connect anymore trusted networks after upgrading to High Sierra.

Tested many work-around procedures (turned off/on WiFi card, tried on different routers, changed SSID of router/s, changed from 5GHz to 2.4GHz band on router, reset MSP on iMac, reset NVRAM on iMac, deleted WiFi settings folder on iMac, reinstalled WiFi card on iMac, clean installation of High Sierra onto an external usb drive, and much more..) but nothing solving.

Also found/installed a clean "El Capitan" OS version onto an external usb drive, the problem disappeared, so clearly not a problem on network card.

Currently in touch with Apple experts to find a suitable solution (OS side ?).

Had the same problem with an iMac (late 2015), went through the same steps. Actually, it was VPN Unlimited that was interfering, trying to connect constantly and aggressively even though not activated.

I did the workaround of advertising my Wifi SSID- This happened back when Sierra came out and only after an update did it re-connect to a hidden Wifi SSID on my iMAC mid 2011 - Funny the MacBook 2015 had no issues nor my iPADS.

Did they forget to test on an older iMac?