I ran numerous tests yesterday and today. All tests 2g.
DAY ONE
(I didn’t take photos of DAY ONE tests you’ll have to trust me)
Installed DD-WRT on my e4200. I ran the recommended setting of AES+WPA2 and NG-Mixed. I tried other settings but there wasn’t any significant change. Speed increased by about 10mbps. With this setup, framework is comparable in speed to my Pixel 2. My Pixel 4 continues to outperform framework by ~40%.
With the above router setup, I installed Fedora 35 Live. No improvement. Pixel 4 still 50% faster.
DAY TWO
I installed a different router the GL-AR300M16. Yes, it is a travel router, but very powerful for its size. Once again, pixel 4 outperforms framework by 50%. My Pixel 2 has comparable speed to framework.
I suspect/guess the router might be configured with “auto 20MHz/40MHz” option on the 2.4GHz channel. This might be causing some issue, see if you can set it to 20MHz not mixed.
Also change “NG-Mixed” to just N unless you have older devices that are only capable of G and need network access. I get the impression you have high radio noise levels in your area so 40MHz is likely a poor option but your router has 5GHz, try it out.
As suggested above me check the adapter itself, pins and receptacle if nothing looks wrong check the laptop with other routers if it still under performs contact support for RMA.
It might seem irrelevant when your speed is below internet bandwidth but if you can provide the actual link speeds between the router and the computer rather than an internet speed test it is more informative.
Here is an example from Fedora but it will be similar on Windows.
The Pixels and FW laptop are 2x2 MIMO device. From what you wrote they are on a 20MHz 2.4GHz N/G mixed network if that is the case a max link speed of up to 150Mb/s (actually 144.4 Mb/s) is possible.
In the real world you should expect about 40% of your link speeds, your picture with the Pixel 4 matches up nicely with this expectation (144.4x0.4 = 57.76Mb/s, MCS 15).
The strange part in that picture is the upload results you shared would not be possible with a 2 stream 20MHz channel so something isn’t right there. Also before you said your old phone (Pixel 2?) got 80Mb/s next to the router? 5GHz perhaps?
It has been a while since I used DD-WRT does is have a wireless page similar to this to show both receive and transmit link speeds?
Yes exactly, the link speed is a measure of the connection between your laptop and the router, the part we are interested in.
See how that speed fluctuates on the locations where performance is bad, you may need to open and close the wireless “2g” page to refresh link speed (now I know why you were calling it 2g not 2.4 GHz ) also look at your RSSI (signal strength) especially in relation to adjacent networks to see if they are causing interference.
It doesn’t explain why the FW would perform worse than your phone but at least it is more information for ideas. Did you check the WiFi cards pins/receptacle for anything that looks wrong?
That speed drop off is very significant especially considering signal (-58) to noise (-70) is still OK. -70 RSSI is your noise level when your 2.4GHz WiFi will start to be the same strength as neighbouring channel 11 signals. You can see that in the 2.4GHz box in you latest picture.
Check for power saving setting in Windows, it might explain the rapid drop off.
Your 5GHz results see much more comparable to your other devices and in the short term I suggest you use that band. You need not limit the 5GHz to 20MHz width use 40MHz
I have not been using windows for over 10 years and well inSSIDer looks very different, a little less informative than I remember and apparently is close source since v3… Perhaps a current Windows user has a better suggestion for feature rich application.
The new wifi card I ordered from framework arrived today. The good news is, I’m very good at snapping in those teeny connectors. I got them in on the very first try. The bad news is my speed at 2g continues to underwhelm. I need this band for the range.
Channel width also made no difference. 20mhz, 40mhz, or auto.
What power settings specifically? I’m running stock windows 11. I never changed any settings. The day I installed windows is the day I assembled my laptop. And wifi runs slow on Fedora Live as well.
Do framework engineers read these forums? I’d love for one of them to make a suggestion.
Have you done any test with other routers? You replaced the antenna and WiFi card so the only other hardware you can change/test is the router. It does sound like interference from other networks is causing issues but I cannot say why it is just the FW that is going slow.
Have you contacted support? I would see if they are able to assist you.
Running any router in mixed mode will almost always slow a laptop wifi speed down. Ideally, you’ll always want to run in the highest/only mode available for all your devices that is the highest speed/throughput available.
My memory is telling me the reason for this is that shared 2.4Ghz and 5Ghz antenna’s can cause a lot of interference. Routers that have separate antenna for the 2.4Ghz and 5Ghz signals are much less likely to have this happen, though some routers have the antenna so close it can still cause an issue.
reveal the LINK SPEED 
) also look at your RSSI (signal strength) especially in relation to adjacent networks to see if they are causing interference.