I needed to upgrade Java so I closed my Brave window by right-clicking the icon in the dock and selecting “Quit”.
When I restarted Brave it asked me which ID to use and I chose the primary one.
I then clicked “[Hamburger menu] History”, the latest tab list (some 13 tabs) and “Restore window”.
The restored window did not appear although the entry in the history list did disappear.
Tried this a couple of times (to negate user issue) but got the same result.
Restarted Brave and got the same result. Have yet to restart my Mac but that’s the next step.
I cannot find any recent reference to this and older reports have just auto-closed with no response.