We are currently running Octopus Deploy v2019.12.1 (and will upgrade to v2019.12.8 on Friday, although I don’t see anything in the release notes about this issue), with the default Calamari version v8.1.3.
Our servers currently have Tentacle v4.0.5 installed, which would appear to correspond to 2019.6.
Health Checks do not report the currently running version anymore. This means that even though our copy of Octopus shipped with Tentacle v5.0.9, nothing is being upgraded.
The log from a health check is attached (with machine names sanitized): ServerTasks-522224.log.txt (1.8 KB)