802.11n monitoring

Today I learned that from the perspective of monitoring wireless networks, 802.11n differs from 802.11b/g in a couple of important ways:

First, there's an option to use 40 MHz channels, where, if I understand correcty, 802.11b/g are limited to 20 MHz.

Second, there's the option to use multiple data streams to increase performance.

Why am I talking about this?

I'm talking about these differences because if you want to monitor 802.11n communications, you need to match the negotiated capabilities between the AP and client you intend to monitor. I've been doing some work involving monitoring a wireless network, and I spent longer than I'd like to admit trying to understand why my AWUS036NH/airmon-ng/wireshark monitoring setup was failing to capture all of the packets. Eventually I came across this question on Superuser about a similar topic. Some smart person responded with a wonderful enumeration of some reasons why I may not see all of the traffic, which made me remember that I used a different client for my initial work.

Specifically, using my AWUS036NH I'm able to capture all wireless traffic from the AP to/from a Samsung Galaxy Tab A (SM-T280), but almost none of the traffic (except some TCP retransmits once in a while) to/from a Motorola Z. My guess is that the Moto Z has more advanced capabilities than the AWUS036NH has, which means the AWUS036NH can't see all of the traffic. As soon as I switched back to the Tab A, I was able to see all of the traffic again.

I'd like to dig up the details of these devices to try to confirm my suspicion, but a quick googling didn't turn up the specifications I was looking for.