Is it possible that there have been some image changes that broke the XR819 wifi completely?
The available images for download on the Armbian page (5.3 server, and 5.4 minimal) as well as a custom built "legacy" branch linux-4.19 image all show the same behavior,
The wlan0 interface is not active and it's not possible to bring it up. And dmesg shows that module has been initialized but not much more.
Armbianmonitor support info:
5.3.9 official buster server image: http://ix.io/240Y
4.1