I've been having issues with 2.3.4.139 since trying to update. Originally the download kept failing. I had to do a soft reset, download 2.3.4.139 then restore from backup.
Once that was done, I had issues with all my devices being unresponsive. After re-initiating the Homekit app, it worked in Homekit, but remained unresponsive in Echo. I tried checking off the option to not wait, but it was not successful. I finally removed the skill & app and tried to reconnect it, however now I get a message that Alexa can not link with Hubitat.
Your Hubitat doesn’t have a proper DNS configuration to reach Hubitat’s cloud.
Are you using DHCP, or a static IP directly configured on your Hubitat? If so, replace it with a DHCP reservation on your router, and configure your Hubitat to use DHCP.
If your Hubitat is using DHCP, make sure that there aren’t firewall rules in place that block it from reaching the internet.
