Thanks for your post. We were advised by Cesanta tech support that this was a temporary fix lasting less than 30 days. They also advised the following:
“Certificates from LetsEncrypt have life span of 3 months.
Our automatic updates trigger 1 month before the expiration day.
Meaning, that if your devices manage to connect, you have maximum 1 month to
update your devices. After that, NOTHING could help you reconnect your devices remotely.
You’d need to go and physically update the certificates.”
What is very troubling is that this has never been a problem for the past 4 years. I can find no documentation on the process of obtaining the ca.pem file and exactly how to update it on our Firmware.