Why is my MacBook Pro M3 Max experiencing slow internet despite fast Wifi?

very often how fast you can run depends on thing is your "network neighborhood" that are not under your control.

if you neighbors change the channels they are using, sometimes that clobbers your performance.

This screenshot from WiFi Explorer, an inexpensive utility with a free trial period, can give you additional insights into what might be going on. This is an example of how crowded the Spectrum around you can get:

...

nobody in this example is getting much done today.

I was having wifi issues with my new machine, but was able to resolve it by turning on Firewall.

Settings > Network > Firewall turn to "active"

Not sure why that seems to have resolved some of the issues.

By far the easiest way to cause poor performance, instability, overheating and crashing is to install ANY third-party speeder-uppers, Cleaners, Optimizers, or Virus scanners, Bit Torrent, or a VPN that you installed yourself. The main reason is that they are relentless in scanning your files, non-stop, looking for virus-like patterns in Everything, or looking for files that have changed. When completed, they do it all again.

¿are you running anything like that?

Then let's look around your 'network neighborhood'. The tools to do this are already installed on your Mac.

Hold the Option key while you click the Wi-Fi icon on the menubar, as before. but this time, choose wireless diagnostics and STIOP. From its Window menu, choose 'Scan' and a window like this opens, click on the channel column to sort by channel-number.

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these newer computer use more modern modulation techniques, and their operating characteristics may change because of that. At the same time, your neighbors are doing upgrades, changing what data channels they are using, and may be clobbering you data in new and unforeseen ways.

I answer many of these queries when posted on the MacBook Pro forums. [in my opinion] there is no such uptick in problems, and almost without exception the problem is not in the newer hardware supplied with these Macs.

Please post your Option Wi-Fi snapshot values for an analysis.

juanabrams wrote:

This has to be a wifi modem issue. I cannot even AirDrop something from my iPhone to my Mac. It first says "Waiting" and after a while it says "Declined" when if it's my Apple ID I don't even need to authorize and if I need to approve I'm not even getting a notification on the Mac to accept or decline. But I don't remember this happening in the beginning so maybe it's one of the software updates

If your local network routing is incorrect, then all sorts of misbehavior is possible.

Check the Wi-Fi router firmware and update to the latest, and restart the Wi-Fo router.

If you have both wired and wireless, then using two subnets is a common choice, or the Wi-Fi router has to present the Wi-Fi as an access point and not routed.

If you have more than one Wi-Fi router, you either must use multiple subnets, or all of your Wi-Fi routers must be reconfigured as access points, or you need to switch over to a mesh mode id that’s supported.

if you could post an Option-WI-FI snapshot, or run Apple Wireless Diagnostics, or both, we would know quickly whether you have a Hardware issue or something else.

Without any hard data, this is all speculation. these issues can be complex, and speculation is not enough to solve these issues.

Check your option-WiFi snapshot agin. see if there is very high interference (shown as high noise).

if that is the display [produced by your Router, and your Mac is listed as the topmost entry in that table, RSSI of -75 dB is simply too little signal for a reliable connection. you need to reduce the distance between your Router and your Mac.

if you want more help with this, please post your Option Wi-Fi snapshot values for an analysis.

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132 to 144 is what you are using when you say 80 MHz wide on 140.

did you verify with a new SCAN that no one else is on that?

Not really congested in the 5GHz range, which is the where the problems area. If there's any congestion at all, it's in the 2.4GHz range, and connections from the Macbook work flawlessly to that radio. If the problem was related to congestion, I would expect every other device connected to the 5GHz radios to have the same problem, and again, only the Macbook has the issue.

Yes, same scan you saw, also what the Mac said I should use. And again, while the Mac was seeing all that packet loss, three other (non-Mac) devices on the same network with the same channel saw no problems. This wasn't a congestion issue, unless the Mac is overly sensitive to congestion relative to other devices. Since the router reboot immediately fixed it, I am sure it was something else.

M3 Max MBP here. I have a RT-AX88U router, the 5Ghz Channel is set for 160MHz, all my devices connect to it fine, the MBP as well, but after a few hours, randomly, it just loses internet, it's still connected to it but there's no internet, doesn't matter if I reboot, turn Wifi on or off, etc.

When this happens if I connect to the 2.4GHz one, it gets internet but barely. I don't really know what to do anymore.

This doesn't affect any of my other devices, iPhone included.

I think there's definitely a wider failure with the M3 chip computers — my 15" M3 MacBook Air has trouble discovering any wifi networks and when it does connect, it only manages to maintain the connection for a brief period of time before losing awareness of all networks.