When operating in Brave, everything appears to be working normally with several tabs open.
If a desktop notification comes through and I click it, Brave closes without notice. When I re-open Brave, all tabs are gone and tabs that were open in the browsing session that shut down do not appear in the browser history. It happens with several different types of notifications, but the notification that caused the shut-down just now was from Trello.
It seems like the error reported in the discussion linked below:
macOS High Sierra v. 10.13.5