I don’t know for sure, but just a thought:
Don’t forget that SSID is just a friendly, non-unique name for the network - the WiFi access point is defined by the BSSID (the Wifi router’s MAC address).
So if you’re connected to SSID “network” on 5GHz, the BSSID might be 11:11:11:11:11:11. And that’s what would get passed via Bluetooth to the Anova unit. But the 2.4GHz BSSID (with the same SSID) might be 11.11.11.11.11.22.
Make sense?