Newly switched from 16.04 LTS to Bionic Beaver. Yet in 16.04 several smb servers were stored to Nautilus server history (or so, sorry don't know the exact terminology). Now after upgrade to B. Beaver file manager (possibly it is still Nautilus, however one source in web stresses it was GNOME's default file manager called Files) the list of servers visited in the past is empty.
How to migrate
generated by 16.04's Nautilus to Beaver's default file manager?
According to System Monitor app Nautilus is in operation (Beaver), no app like Files is listed over there.