Alfa card scans networks for a few mins and only when replugging it into USB port

I am running Kali Linux (2020.1b 64bit) via VirtualBox (6.1) on a macOS host (10.15.4) with a brand new Alfa AWUS036NH network card attached via USB.

The network card is recognised by Kali Linux and is set to monitoring mode:

$   iwconfig                                                                                                                                                                                                                                                                                                       lo        no wireless extensions.                                                                                                                                                                                                                                                                                            wlan0     IEEE 802.11  Mode:Monitor  Frequency:2.427 GHz  Tx-Power=20 dBm                                                                                                                                                                                                                                                             Retry short  long limit:2   RTS thr:off   Fragment thr:off                                                                                                                                                                                                                                                                  Power Management:off 

However, when running airodump-ng wlan0, no wireless networks are discovered despite there being numerous.

I have noticed that by physically removing the adapter and re-plugging it back into the USB port, I am able to get the card to discover the nearby networks. This does not always work, but it is the only scenario that I am able to get it working. Furthermore, whenever I get it “working”, this state is short-lived and the networks disappear within a few minutes — and then silence.

What could be causing this unusual behaviour and what diagnostic tests can I run to narrow down the cause?