New Macbook Pro M3 slow wifi since setup

<<. If I unplug the HDMI cable from the M3 machine, the connection speed immediately comes back up. >>

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.

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.

RSSI is raw signal. -40 is right next to your Router. Your measurement, -77, is unacceptably BAD. You appear to be too far away from your router for a reasonable connection.

If your Router is within a few feet, you have a hardware issue such as disconnected antenna wires.

maybe it can help someone. I realized, that the WIFI problem is connected with the HDMI port. If I use USB-C port instead for external display WIFI is working.

Seems to be a hardware issue, not sure if all Macbook Pros M3 are affected. My old M1 or Windows Laptop is working fine with that cable and display.

I have the same issue. I solved it.

I have an external monitor connected directly to my laptop via an HDMI cable. I unplugged the cable. Then the upload/download wi-fi speeds shot back up to normal. I re-attached the external monitor but using an HDMI dongle that connects to my computer via USB-C. Wi-fi speeds are still fast. Thus, I've pinpointed the issue to the HDMI port itself. So this HDMI port is practically useless.

if you post your Option Wi-Fi snapshot, a whole lot of inferences can be drawn from its information.

based on an analysis of that snapshot, one user ultimately discovered they had a disconnected antenna lead in their MacBook. Some users are surprised to discover they connected on one band when another was readily available. Some users discover the observed Noise I higher than expected, or signal is FAR lower than expected. Some users found badly-shielded USB devices were interfering. Some users found that the difference in modulation techniques supported by older and newer Macs allowed their neighbors routers to clobber more modern data, but older data went though unscathed.

That is why I suggest you post that. It is FULL of pertinent information!

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

Dressed the cables away from the hinge area of a MacBook Pro, or away from the base of a Mac Studio. that is where the wi-fi antennas are located. and/or obtained CERTIFIED cables.

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

Hi Grant,

This is definitely not a WIFI router / signal issue. I have my new M3 sitting on the same desk as my M1 machine - equal distance from the router. The M1 machine has full signal and fast download speeds. The M3 with an HDMI cable plugged in has full wifi signal but very low to no download speed. If I unplug the HDMI cable from the M3 machine, the connection speed immediately comes back up. This is clearly some kind of hardware issue with the new M3 machines.

@CosmoKramerNewman

yes... that is exactly same behavior with my M3 pro - there is almost no connection if I use HDMI port. Funny thing, if I use same HDML cable + same Display but with a USB-C to HDMI adapter, I have no wifi problems. I have it at home and at my office.

Did you already visited an Apple Store. Maybe only some M3 are broken not the complete series. I didn't had the time until now to go there.

And to be honest I'm afraid, that I they will tell there same stories, like here in the support community about bad cables, broken WIFI routers, bad USB devices, bad neighbors. Although my M3 is the only device which is not working with HDMI + WIFI in my household and company.

Hey guys, I had the same problem and I will tell you how I fixed it, in my setup I was using a monitor and every time I connected the HDMI to my MacBook Pro m3 pro, I lost my internet connection, first I thought it was a problem with the HDMI-port but the problem was that my monitor was also connected to my wifi, that's why I always lost connection. So just turn off the wifi of your monitor and normally it will fix the problem.

Hope this fixes it for everyone with an external monitor

Try disabling IPv6:

Ventura: System Settings -> Network -> Wi-Fi -> Details -> TCP/IP (tab) -> Configure IPv6 -> Link-Local Only

I found this, that seemed to fix it

Hi,

Had the same issue.

Went via Apple Support and after connection and RJ45 dongle and Cat6 cable, seems the MBP is OK, it's either the wi-fi hardware or driver issue. Apple suggested either re-install the OS or take it in for repair.

I have the same problem with my brand new macbook pro m3. My old m3 does not have the problems. I read something about problems with 5GHZ. So I switched back to 2,4GHZ. Seems to work better.

By the way I'm using TP-Link Deco M4.

You're right!

I changed the position of the devices on my desk, now everything is working perfectly!

I'd never imagine this. Thank you a lot!

Absolutely the same problem.

Using a M2 side by side with my new M3 in the same spot, I constantly loose connectivity on my M3 whereas the old one is fine.

If I have anything plugged in one of the M3's USB-C ports the WiFi drops constantly.

Any further ideas/advice?