When I first run the latest nightly builds on macOS, an eXist-db icon appears in my dock. This icon doesn't close when I quit eXist via the menu bar. It seems the only way to get this icon to go away is to control-click on it and select quit. But it's odd, since it's not associated with the eXist-db process.
Since this persistent dock icon only appears once - on first run of a new installation - my hunch is that this is somehow related to something that only happens on first run and not subsequent runs. But I'm not sure what it is.
It seems harmless but could confuse users. The "normal" behavior I would expect from eXist-db is that the dock icon appears briefly and then disappears after the menu bar icon appears.
I'd be happy to file an issue about this if the developers would like.