The thing is that dash-to-dock also adopts Ubuntu Dock settings, since that is what Ubuntu Dock is based on. So if I remove Ubuntu Dock, for example, but then install dash-to-dock, it actually starts in panel mode. (that is not a default) The fact that this bug does not seem to occur in Fedora 30 with dash-to-dock (v66) installed makes me believe it is some Ubuntu Dock specific thing, but I am just speculating atm.
@carlosjosepita
The thing is that dash-to-dock also adopts Ubuntu Dock settings, since that is what Ubuntu Dock is based on. So if I remove Ubuntu Dock, for example, but then install dash-to-dock, it actually starts in panel mode. (that is not a default) The fact that this bug does not seem to occur in Fedora 30 with dash-to-dock (v66) installed makes me believe it is some Ubuntu Dock specific thing, but I am just speculating atm.