I installed the 10.2 update on 16 March and on 2 occasions since then when I have opened Lightroom it has reverted to opening as if it was a new install with a complete reset of preferences and asking if you want to import an Elements catalog to get started. It appears to be random and not just the first time I open Lightroom each day. Any thoughts on what might be causing this would be gratefully received.
If you are resetting preferences, this could conceivably happen (although it has not happened to me). Make sure the setting in Lightroom Classic preferences say that you want to open a specific catalog.