Tested on Metro ESP32-S2 and MagTag. This was also present in a debug firmware for MagTag provided by @tannewt on 17 Nov 2020.

On CircuitPython-6.1.0-beta.0, the wifi module will sometimes hard-reset on wifi.radio.connect(), using a small connect script (*) This seems to only occur on Ctrl-D and save-on-reload restarts. When starting from hardware reset / power-on, the script works.

Also on CP-6.1.0-beta.0, it seems the ESP32-S2 WiFi cannot connect to APs that are not DHCP servers (but instead use a DHCP server over LAN). I have two APs on my network: one is the router and DHCP server, another is secondary AP (with different SSID) on the same LAN as the DHCP server. The ESP32-S2 CP can connect to the primary AP that's the DHCP server, but will error out with Connection Error: Unknown failure on the secondary AP. This almost feels like the ESP32-S2 is timing out early for a DHCP response.

*e.g. a script such as:

import wifi
for network in wifi.radio.start_scanning_networks():
    print("\t'%s'\t\tRSSI: %d\tChannel: %d" % (network.ssid, network.rssi, network.channel))
wifi.radio.stop_scanning_networks()
print("connecting...")
wifi.radio.connect(ssid="mysssid", password="supersecret")
print("connected.")