After looking at my config I can confirm that ‘dtparam=ant2‘ was indeed missing. Perhaps I missed that instruction when I did my initial installation.
I’ve added it to my config, below other global dtparams:
> sudo cat /boot/firmware/config.txt | grep -A3 -B3 ant2
dtparam=audio=on
# Enable external antenna on the WiFi chip
dtparam=ant2
# Additional overlays and parameters are documented
# /boot/firmware/overlays/README
and rebooted and connectivity has improved.
Is there a way to probe the wifi-driver for which antenna is in use?