Placing stuff into /lib/firmware on NixOS is completely ineffective, because the kernel, like almost everything else on the system, does not use global directories to function. You need to configure the correct NixOS option instead.
It’d be easier if you posted your complete config, but just as a first guess—have you enabled unfree firmware with hardware.enableRedistributableFirmware = true; somewhere? You should.
My laptop should be coming back soon. Funny…I thought after about a month, we should be seeing 6.11 by now, but we’re still on 6.10.12. Is the QCNCM865 working on any of the released kernels yet? Or still waiting for at least 6.11?
I had to compile my 6.11 originally. The 24.10 Ubuntu with 6.11 should be releasing on Oct 13 with the 6.11 kernel installed already, or if you need it right away the beta has 6.11.
Can’t say about 6.10.x.
I’m on 6.12rc2 now, and working perfectly (just like 6.11)
Just received my QCNCM865. Wi-Fi works OOB on NixOS with linuxPackages_cachyos (6.11) 
The only issue right now is audio through bluetooth. Let’s wait for an update!
Oops, I just tried on a wifi 7 AP. Previously on a WiFi6 AP I was able to get 1Gbps. WiFi 7 give me less than a single Mbps…
This is with your QCNCM865 on NixOS?
Yes exactly. Both experiments using the exact same hardware and OS. W/ FW16 now being WiFi 7 compatible and my phone being only WiFi 6 compatible:
Hy guys,
as this Post was the first hit in my search, I read a lot about the current situation about the Linux support of QCNGN865… and finally found that the last post was just some hours ago.
As I bought a new WiFi7 router yesterday I wanted to update my Linux Laptop. I already found out (the hard way) that the Intel BE cards would not work in my AMD system, and there is no hope for an UEFI update.
I searched and found the QC card, thanks to the information you provided I could cancel the order.
So even I don’t have a Framework laptop, the information you provide and the effort you put into this thread is really helpful for other people, thanks.
I will still have a look on this, and on the market for upcoming products.
Kind regards.
My recent test of QCNGN865 with Framework 13 AMD (Fedora 40 with kernel 6.11.0 from koji).
Bluetooth mouse: works
Bluetooth headphones (Google Pixel Buds Pro): can’t connect
WiFi speed to AP WiFi 6 (Asus RT-AX86U) compare to built-in WiFi card by fast.com:
The closest location to AP: ↓620/↑680 Mbs vs ↓630/800↑ (built-in). Latency: 3/8 ms vs 3/9 (loaded/unloaded).
The farthest location: ↓280/↑270 vs 190/200. 3/51 vs 5/87.
Summary: wireless audio still doesn’t work. WiFi 6 connection is OK, but not the best one.
Interesting, mine are working just fine, as are my Pixel Buds Pro 2 ones.
Just for some context I’m using Ubuntu 24.04 with mainline kernel 6.11 currently, but previously 6.9 and 6.10 worked as well with no issues that I can remember.
Edit: Just tested with a different random set of Bluetooth earbuds I had laying around, they did not work properly. So there is for sure something bugged with Bluetooth. Not sure why my Pixel Buds work and yours don’t it must be some sort of luck of draw situation.
Did you try to use bluetoothctl to connect to the headphones?
6.11.3 is now released on Fedora! Big jump from 6.10.12 (I guess all the other iterations were just testing).
Unfortunately my FW16 still haven’t come back from RMA. It’s been 1.5 months now. 
The audio connection issue might be related to Bluetooth transmission power. For example, in my case, I can connect to everything that uses audio without any problems, but I’ve noticed that the highest quality codec can sometimes cause choppiness. I’ve had to lower the codec quality to stabilize the connection and when moving around I can experience choppiness again, more than with the mediatek card that I had before. I should experiment a bit more by extending the buffer. By the way I am on 6.11.3-350.vanilla.fc40.x86_64. But as I said I have not experience connection problems, quick tip if you have multiboot you have to unlink and relink the bluetooth again as the system share mac address but not keys… There are other automatical configuration for this case if you do it often…
Wi-Fi connectivity has been excellent—I’m able to connect to access points that used to glitch with Mediatek hardware in the past, so I’m pretty happy with that improvement. But bluetooth works just good enough, I dont normally use the bluetooth mouse but I cannot feel any drops there, so it might also be codec related.
All this talk of BT issues sound like a reception issue than driver? I hope there is a good WIFI7/BT card for AMD/Linux.
What’s interesting about the one device I couldn’t get sound from, is that it did get connected to Bluetooth just fine, but in my case at least Ubuntu refused to detect it as an audio device.
Are you using pipewire or pulseaudio ?
Whatever the default is for Ubuntu 24.04 (Pulseaudio I think), frankly I think I probably need to replace pulseaudio at some point.
So maybe there is two issues, one about pipewire, and one other about low power