So I might have a possible fix, but it’s more like a band-aid -
On a whim I went ahead and basically bypassed network manager completely by disabling the service in systemd, then I created my network in /etc/network/interfaces and its associated wpa-conf file in /etc/wpa_supplicant and connected to the network without the use of network-manager.
Much like the workaround procedure in: https://bugs.96boards.org/show_bug.cgi?id=272#c17
Then I started my ping tests and saw that after ~3 hours of sustained pinging that I had 0% packet loss from both desktop->dragonboard and dragonboard->desktop.
This pointed me towards an issue in network-manager! Now I know that the default behavior for network-manager is to periodically scan for networks while we’re in the connected state of the adapter, this is to probably aid in roaming from AP to AP in a corporate wifi environment.
So I did a little digging and fell upon this page in the archlinux wiki - https://wiki.archlinux.org/index.php/NetworkManager#Regular_network_disconnects.2C_latency_and_lost_packets_.28WiFi.29
This page pointed me to a repo with a patch for network-manager where we disable the periodic scan behavior -
I then got the source for our network manager via apt and applied the above patch, compiled, and installed the patched version of network-manager after reverting my changes to /etc/network/interfaces and enabling network-manager via systemd.
Now after about ~20 minutes of pinging to and from the dragonboard, I have 0% packet loss. I am hesitant to say that this fixes the issue entirely, but it seems to be a lot more stable than it was with the periodic scanning enabled. I encourage others to give this a shot to see if things are more stable for you while using WIFI and network-manager.