Hi @zeke – good check by Rick.
Looking at your error, it does say connection error so implies it didn’t even connect to thingspeak.
I checked this 5months ago and it worked for me. What is your channel number?. This allows a view of if any data has arrived. The channel I used for testing, a bit simplistic https://thingspeak.com/channels/5940
You could also enable some debug and share it.
For platformIO this is