Wifi 5GHz stops working after connecting USB-C hub!

Question

Level 1

6 points

Wifi 5GHz stops working after connecting USB-C hub!

Hi, I have MacBook Pro M2 and whenever I connect USB-C hub to it my 5GHz WiFi connection stops working or the connection is working very slow. There is no issue on 2.4GHz network (the same router)

I've tried all 3 USB-C Ports (on the left and on the right side)
I've tried to use longer cable an move away from the HUB
I've tried to "forget" this network and configure it again

The same HUB works great with my Macbook Air M1 and 5GHz WiFi connection

Please do not write that the HUB is broken (it works with my Lenovo laptop on Win, MacBook Air, and old MacBook Pro 2012) and there is no issue with 5GHz/2.4GHz WiFi.

Please do not write that the HUB is generating special frequencies and blocking all radio communication in the neighborhood because this is basically not true. Why it is not blocking communication of MacBook Air/Lenovo laptop/Iphone that is laying next to it? There is clearly something wrong with the specific MacBook model.

The HUB is Lenovo DK1633 40A9.

Apple please investigate it! This is unacceptable. People are buying Your new products and have to switch to old technologies like 2.4GHz to use it?

If this is normal behavior of Your product please write it clearly in the description that 5GHz WiFi is available only when no USB-C HUB is connected. So people can make the decision before buying it.

MacBook Pro (M2 Pro, 2023)

Posted on Jun 28, 2023 9:02 AM

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Answer 1

Jun 28, 2023 7:46 PM in response to Grant Bennet-Alder

There is only one case where a badly shielded display caused so much local interference it knocked a nearby router off the air:

• LG-display recall -- to address Wi-Fi interference so severe, it knocks the Router off the air if too near the Router.

https://9to5mac.com/2017/02/03/lg-fixes-wifi-interference-problems-with-ultrafin e-usb-c-5k-display-new-units-unaffected/

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Answer 2

Jun 28, 2023 7:44 PM in response to Quinametin

Far, far more complaints come from using badly shielded USB-C peripherals when using ONLY 2.4 GHz Wi-Fi, because USB-c radiates into the 2.4 GHz range, and a badly shielded peripheral can disrupt 2.4 GHz Wi-Fi.

Keep in mind that disruption can be extremely localized, and falls off so quickly that simply moving the peripheral to the other side of your Mac may solve the problem completely. This is my accumulated advice:

Why do I have difficulty with Wi-Fi or Bluetooth devices when USB 3 devices are attached to my computer?

Some USB 3 devices can generate radio frequency interference that can cause Wi-Fi and Bluetooth devices operating in the 2.4GHz band to have issues communicating with your computer. Here are some tips to avoid this issue:

• If your USB device has a cable long enough that you can move the device, place it away from your Mac—and make sure not to place it behind your Mac, or near the hinge of its display. The antennas for Wi-Fi and Bluetooth are located there, and USB 3 devices placed there might interfere with your wireless connections.

• If you're using adapters or dongles on a Mac computer with Thunderbolt 3 (USB-C) ports, plug them into the front port on the left side of your Mac, or into the ports on the right side (if your computer has them). These ports are the farthest away from the antennas, making interference less likely.

• To avoid interference on the 2.4GHz band using Wi-Fi, try using the 5GHz band instead. You can change this on your wireless base station. Bluetooth always uses 2.4GHz, so this alternative isn't available for Bluetooth.

from:

About USB on Mac computers - Apple Support

Resolve Wi-Fi and Bluetooth issues caused by wireless interference

Resolve Wi-Fi and Bluetooth issues caused by wireless interference - Apple Support

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Answer 3

Quinametin Author

Level 1

6 points

Jul 3, 2023 6:28 AM in response to Grant Bennet-Alder

Hi everyone,

Thx for the answers and suggestions. I have asked Apple support for help and having them online I've tried to boot the MacBook in save mode, removing wifi settings and at the end I have been advised to reinstall OS.

I was not very happy about it so I tried to dig deeper. I started disconnecting my devices from USB HUB and found out with only my Philips LED screen connected that the issue is still there. But when I disconnected the screen the issue was gone :)

So I disconnected the screen from USB HUB and connected it directly to the HDMI port on the MacBook. The issue was back again. I run ping command to some popular IP address (8.8.8.8) and I was watching the time rising to 4000ms and finally got timeouts.

When I tried to disconnect the HDMI I have put my fingers on the connector and before pulling it out I saw the ping time go down to 200ms

So I took the HDMI connector a little bit out (but not too much, not to disconnect it) and I've touched the metal shielding. Suddenly the ping time went back to normal 14ms. Booom! There it was.

So the next step was getting a different HDMI cable. I found a new solid one. After connecting it the issue was not there anymore :))))

Success!

Summing up:

there was some issue with the shielding of the HDMI cable
but why the same LCD screen is working using the same (old) HDMI cable with other MacBook Pro 2012, MacBook Air M1, Windows laptops and not interfering with 5GHz WiFi? No idea, this is the case for Apple or Philips

I hope it will help someone else having this issue in the future

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Answer 4

Jun 29, 2023 6:41 AM in response to Quinametin

now that we have talked about what was expected to happen, andd does not appear to be the case, let's dig in and and see what's really happening to you.

Hold down the Option key while you click on the Wi-Fi Icon on the menubar, and several new Options appear. One is that a snapshot of your current operating conditions appears. Transcribe or screenshot the items listed there and post back here for analysis. It resembles this older one:

.

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Answer 5

Quinametin Author

Level 1

6 points

Jun 28, 2023 10:33 PM in response to Grant Bennet-Alder

2.4GHz works flawlessly. Only 5GHz is being disrupted.

If my HUB (or my screen or any other device connected to the HUB) is creating interference on 5GHZ frequency why is it disrupting connectivity only of this specific MacBook Pro?

Why it is working with MAcBook Air, MacBook Pro 2012, Lenovo ThinkPad, HP laptop?

It is still the same frequency (the same channel). It is clearly an issue with this specific MacBook model.

Maybe badly shielded elements on the mainboard?

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Answer 6

Jul 3, 2023 8:20 AM in response to Quinametin

Your display has only Analog VGA, DVI and HDMI inputs (no DisplayPort family).

HDMI was invented for HD TV sets. it works great at its original resolution of 720i or 720p. At higher resolutions, it quickly develops issues that are complex to solve, and the cables and adapters required to solve are NOT intuitive.

HDMI cables you want for HDMI-only Displays (higher resolutions than 720p TV sets) are marked as Certified with an anti-counterfeiting tag and are labeled:

"Premium High Speed HDMI cable" or that + "with Ethernet" --OR--

"Ultra High Speed HDMI cable" or that + "48G"

Cables with No Certification tags are good for your standard 720p TV set, and not much more.

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