I had a project using an ESP32 to transmit temp and humidity data from a sensor and Open Weather Map to Adafruit IO. The project was working for several weeks (I've got lots of data points in my Dashboard still). After updating my Mac to Big Sur, the first code update I compiled no longer connects to Adafruit IO.
To troubleshoot this, I have uninstalled Arduino and all related directories and re-installed all boards and libraries. Using examples such as the Sparkfun ESP32 Examples > Time > Simple time (which just uses WiFi.h), everything works fine (and my project is now using this as a workaround). When using Adafruit IO examples such as "adafruitio_00_publish" with the default config.h (with my credentials updated appropriately), I get the endless "." (or when using statusText() I get "Connecting to Adafruit IO," "Network disconnected," then endless "Disconnected from Adafruit IO") in the Serial Monitor.
I've been able to confirm that the code does seem to connect to the internet, as the device appears in the connected devices on my router and I can successfully ping the ESP32. The issue appears to be related to actually connecting to Adafruit IO. I have regenerated my IO Key and updated my config.h, but have been unable to get any code to successfully connect to Adafruit IO and am at a loss on what to troubleshoot next.