My Latest Milestone and Latest Solid Subtangle Milestone are the same, but they do never change and they are behind the numbers in #botbox. What does that mean? My node is not fully synced, right? What can I do against it, if my assumption is right?
Yep, you are out of sync
You could ask in the #nodesharing channel for a few new neighbours. Perhaps you chose some dead ones. You can detect dead neighbours if they are also behind
Additionally, try to restart your node. There are some weird syncing issues with the current iri version, this sometimes seems to fix it