Hi,
I was advised to use a QCA9880 Dual-band WIFI-card Mini PCIe since it was supported by the Mikrotik.
So I purchased and inserted a wireless QCA9880 (mini-PCIe) into a RBM33G.
However Winbox does not detect this wireless interface.
Does it mean that this PCIe will never work on this RBM33G or is a firmware or OS upgrade required?
Since you do not specify which ROS version your device currently is using, who knows …
What strikes me as odd is that this specific card is discontinued (if you are referring to R11e-5HacT)
From what I can quickly see, it should work, however.
I also see you had the same issue with Atheros AR5B22 in combination with that RBM33G.
You were also there advised to use that one.
Advised by who then ?
The MikroTik was shipped with RouterOS 6.48.6
The Atheros AR5B22 was advised by the local routershop. They stated that all Altheros / Qualcomm PCIe’s should work. I guess they were wrong.
The QCA9880 was not R11e-5HacT, but ordered on Amazon since QCA98xx should work on a MikroTik (https://www.amazon.nl/QCA9880-Wifi-Netwerkkaart-Netwerkkaart-802-11ac-Plug/dp/B0BXDQBGS3).
It was shipped with 6.48.6, what has it now ?
You can already upgrade to latest ROS6 (6.49.13 long term or 6.49.17 stable)
If it doesn’t work using ROS6, try ROS7-chain.
You can upgrade to latest ROS7 BUT be careful, since your device only has 16Mb flash, storage might become an issue.
MMIPS platform is anyhow a dead-end … (I’m holding on to my Hex for as long as it runs and it runs ROS7 just fine 
)
Wireless package installed?
I have upgraded to 7.16 and installed the packages, but the RBM33G is still not recognizing the QCA9880 PCIe WiFi.
Am I missing something?
https://drive.google.com/file/d/1XSHWsYuTXXDwwB3xF-MawJSsufFa4_cH/view?usp=drive_link
In my view, here is your problem:
The QCA9880 was not R11e-5HacT, but ordered on Amazon since QCA98xx should work on a MikroTik
Clearly it doesn’t. Not when mounted on a non-Mikrotik PCIe card.
That is a pity. As long as I did not forget something simple like a dipswitch on the motherboard or enabling the wireless package…
Poleke, did the QCA9880 work on the RBM33G? I'd like to perform the same setup.
No it didn’t. I have not yet a working setup….