I am using a BCM943341WCD1 evaluation kit with the WICED SDK 3.3.1.
I have coded a fairly comprehensive application that performs two operations. First, it surveys the environment using wwd_wifi_scan() in both active and passive modes and builds a table of all APs that it finds which turns out to be a list of dozens of them in both the 2.4 and 5GHz range in the environment where I am running it.
Then I have the code change modes and monitor all packets using wwd_wifi_enable_monitor_mode() and wwd_wifi_set_raw_packet_processor().
While monitoring, I added some code to check every MAC address in the raw frame (addr1, addr2, addr3) and compare it to see if it matches any AP that was found in either the 2.4GHz or the 5GHz range of addresses. It finds many packets with addresses that match the 2.4GHz APs, but it *never* finds any that match APs in the 5GHz range despite having equipment in the room that is connected to 5GHz access points and generating a fair amount of 5GHz traffic. Since the code works fine and finds many packets in the 2.4GHz range, I have reason to believe that the code is working correctly.
So, is there some missing magic sauce to get the monitor mode to actually monitor for packets in the 5GHz range or maybe this does not work on the platform?
I reproduced the issue on BCM943341WCD1_2 and SDK v 3.5.2 by configuring one of the routers to 5GHz Bandwidth and Scan App does list that AP on the UART. As the BCM943341WCD1 supports dual band I don't see any reason why it should not work.
Here is the screenshot of the UART.
Maybe I failed to mention that I can see 5GHz access points when I scan for them, just like your experiment shows. But it never produces any packets in the 5GHz range when you enable monitor mode - wwd_wifi_enable_monitor_mode(). So, I believe that your experiment is not reproducing the problem that I am seeing.
Also, as confirmed in other questions I have asked on this site, setting the channel before enabling monitor mode has no effect because I am told that it always monitors for packets on all channels, which I don't believe until someone shows me that they can collect a monitor mode packet that was transmitted in the 5GHz range. It would also be helpful if when a packet arrives, it said what channel the packet was received on, which it does not.