SSL Failure for IoT Devices using Let's Encrypt Cert

I’m hosting a backend for IoT devices and the certificate I have loaded on my devices is now failing to connect. My devices all have the Let’s Encrypt R3 cert on them. When I hit the health endpoint of my service in a browser I see a cert from Cloudflare Inc RSA CA-2 that goes to Baltimore CyberTrust Root. The Let’s Encrypt R3 cert worked as recently as Oct 16th when many of my devices successfully hit my Render service. What has changed?

It turns out this is part of a one time rollover Render is doing to put everything behind Cloudflare. Unfortunately there was no notification that the cert would be changing. Render support has taken care of helping me on this and will hopefully communicate changes like this in the future.