But it did install Tailscale. You wouldn’t have received the error if it didn’t. The error was caused by cloning one machine to another machine. Because it was cloned, the Tailscale configuration from the first machine also got cloned to the second machine which includes the IP address assigned to that machine. The error occurs when trying to connect to the tailnet because you can’t have two machines with the same IP address on the same network at the same time.;
Cloning a machine to another and running both at the same time is not something openHABian supports nor is it something openHABian claims to support and it’s not a very common procedure. The supported approach is to install from scratch and restore a backup instead of cloning the machine.
If someone wanted to submit a PR to handle this use case I’m sure it would be accepted, but I doubt any current maintainer would implement it.
As for Frontail, that’s just shows what’s in the openHAB logs. It doesn’t do anything with time itself. That is something OH related. In all likelihood your regional settings are not correct in the operating system, or for Java. There are several threads that go through all the places to look and things to fix there. Here’s one: TimeZone DST - Log shows 1 hour behind