Trouble capturing data frames on 40Mhz (or 80Mhz channels)

Hello all,

I am having trouble capturing data frames on 40 & 80 Mhz wide channels.  My situation and efforts are described below.

WLAN cards used: Alfa AWUS036ACH, Alfa AWUS051NH (everything below was done with the AWUS051NH)

OS:  Kali 2017.1, updated ...