This has been fixed, the keyserver in GPG Keychain was not set to keyserver.ubuntu.com 
It might actually be a good idea to host the public-key on https://artifacts.chirpstack.io so people can pull it directly from there instead of using keyserver.ubuntu.com. Some people have had issues with that in the past so this solves two issues.
You should re-run the following command to fetch the update:
sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 1CE2AFD36DBCCA00
Please let me know if that solves your issue (it did for me).