New MacBook Pro WiFi connectivity dropping rapidly

Wi-Fi slow and/or disconnecting— current accommodations include:

Updating software:

• if on Monterey, Updating to the very latest version of Monterey.

Reducing number of networks being evaluated:

• Checking the [√] ask to Join new networks check box:

AND purging the list of potentially-available networks in this pane:

System preferences > Network > Wi-Fi > (Advanced) ...

... to leave ONLY the networks you might really join:

>> all of these reduce the number of networks your Mac is evaluating on a moment-by moment basis, looking for a better connection.

IPv6:

System Preferences > Network > Wi-Fi > (advanced) >TCP/IP > IPv6 ... to Link-local only

ON may cause routing activity that interferes with your networking.

OFF will make it hard to find printers and other services on your network.

“Limit IP address Tracking” has been shown to be an issue on some Networks:

< Limit IP address tracking >

VPN:

If you have enabled ANY VPN features in system preferences > network

these can interfere with regular network operation.

If you are using a VPN you installed on your own, remove it while continuing to debug.

Also remove ALL devices in the left pane related to VPN in:

System Preferences > Network

If this VPN is for an Institutional/Corporate connection, contact your institution for additional guidance.

80Mhz channels:

If your 5GHz band is configured (on your Router) to 80MHz channel-width, some users have reported problems. If they reconfigured the 5GHZ band to back to 40MHz channels, many of their connection and speed problems evaporated.

Network Location:

If you continue to have trouble after using these steps, create a new named Network "Location" -- a collection of settings applied "all at once" when you select it. Every new named "Location" you create starts with all defaults, which lets you walk away from any errant settings that might be causing you trouble:

How to use network locations on your Mac - Apple Support

How to use network locations on your Mac - Apple Support

.

You asked about maybe broken antennas. The test for that is to walk your MacBook in next the the Router and look at RSSI. you need to be getting between -40 and -50 right next to your Router, and if you are not, your antennas are disconnected or broken.

You mentioned your apartment. In an apartment building, the main enemy is too many other Routers around you. The defensive solution is to NARROW your data channels to the minimum, in hopes of Not getting your signal stepped on by your neighbors. an 80 MHz channel over which you get 1 M bits/sec is not a win.

I was at my local Apple store, and discovered it was completely saturated your different Routers, each on a very narrow channel. Reception was great, throughput was just fine. I except if I moved too far in any direction, it would just "roam" to another Router on another channel.

The default Router setup is often to create only one name for BOTH radios, and offer either/both connection there. The choice of which band will actually connect is arbitrary.

When you create TWO distinct names, one representing the 5GHz radio and one representing the 2.4GHz radio, you can simply choose 'connect to' under the Wi-Fi menu, and choose the one you like. MacOS latches onto that and is reluctant to let go.

--------

In the manual I can find online, the 2.4GHz default name is ALHN-A109, and the default 5GHz name is ALHN-A109-5

on your snapshot with Raw signal RSSI at -59dB, conditions are far worse. MCS index (how many patterns per signaling interval can be supported steady-state) has fallen, and the data rate has dropped dramatically to 146 M bits/sec Transmit rate.

------

the snapshot at -60 should have enough raw signal to continue, but it at only 8 M bits/sec on a 80 M Hz channel it is doing worse than baseband, and has all but disconnected.

Both of these later snapshots could indicate that you have inference from other Routers, not necessarily on your main channel, but using adjacent channels that are partially interfering.

There are two good ways to proceed:

one is to find out where the other Routers are, look at the Spectrum spread (how many adjacent channels are getting used by their data) and go somewhere else. look back at the Wi-Fi explorer black "spectrum" maps I posted earlier for some idea of what that is about.

The other is to significantly NARROW the channel you are using, reducing the likelihood that another router will directly clobber your data. To do this, change the channel width from it current setting of 80 to a lower number like 20.

Hold down the Option key while you click on the Wi-Fi Icon on the menubar. You get a snapshot of the current conditions, similar to this older one, transcribe or screenshot your snapshot and readers can advise:

Many users prefer to tune 'which band' they connect to under different circumstances.

This can be accomplished on the Router by giving the different 2.4 and 5GHz bands slightly different names. it is incredibly common the see MyRouter and MyRouter_5G anywhere you go. (where MyRouter is your network-name of choice).

Then connect to the name you like better for a certain situation. (The router immediately merges them back into the same network internally for most purposes).

Then re-enable the advanced features and post an Option-Wi-Fi snapshot of the result.

there is nothing bad showing there. you are on 5GHz radio, RSSI saying right next to the Router, using both of your two antennas to get the absolute top speed on the channel you have selected 112. Noise is reasonable at -90dB.

How did you choose that channel?

When you set the Router to "auto", when the Router powers up, it listens for a moment, and chooses a channel that seems less used. It is not an accident that every debugging procedure start with "cycle the power to your Router" because that will select a less busy channel. However, if one of your neighbors decides to do a heavy download on an adjacent channel, you performance could go bad in a hurry.

-------

Next, I suggest you take the next snapshot at half to two-thirds the distance to the drop-out point, and see what happens there.

-70 is really not enough raw signal. There is no point trying to micro-analyze other factors. You are 5dB worse that "ready to spontaneously disconnect". If your other devices are getting by, that is fairly miraculous.

You need to look at some different solutions such as relocating your Router, adding an additional access point, running some Ethernet cables, or using a powerline Router or Switch.

There are some tools in MacOS that can help you see what channels around you are currently in use. They are accessed by holding the Option key while clicking the Wi-Fi icon on the menubar, then choosing "network diagnostics". they include:

1) Assistant

2) Info

3) Logs

4) Scan

5) Performance

6) Sniffer

https://9to5mac.com/2016/07/14/how-to-understand-wireless-diagnostics-app-on-mac-to-analyze-improve-wi-fi-network/

Scan looks like this:

.

that video is really interesting, mostly for what it does NOT show. They appear to leave the Router on the floor.

Do you have enough cable to lift the Router off the floor where they place it, to say, standing head height? Do they provide a wall bracket?

can you please post the Option-Wi-Fi snapshot of your NEW Mac when close to the Router?

the one you posted before had such poor RSSI it was not usable for detailed analysis.

I also recommend a tool that has a brief free trail, that in addition to raw channels will show Spectrum. It is called Wi-Fi Explorer:

.

wait, that's in the same room? that RSSI (raw signal) is awful!

close to your Router you should be getting around -50, or slightly closer to zero. As you go father away, that number is expected to drop off,

When it reaches -65, your Mac or iPhone will actively try to switch to any other network in range.

Wherever that is, you are already too far from your Router for a good connection.

Set to 802.11n and using the 2.4GHz band, 144 M bits/sec is as fast as you can go, using two antennas and 64-patterns per signaling interval. Your hardware appears to be working under these circumstances.

Anything faster requires the 5GHz band and a more advanced scheme such as 802.11ac or ax, which you said you have turned off.

Many users prefer to tune 'which band' they connect to under different circumstances. This can be accomplished by giving the different bands slightly different names, and connecting to the name you like better for a certain situation. (The router immediately merges them back into the same network for most purposes).

If you are satisfied with the way it is working, you are done, and that is great.

If you want to work on the WHY, you will need to get closer than drop-out range, connect to the 5GHz radio, and collect that snapshot for readers to analyze.