Description of the issue:
My phone automatically restarts every night, one morning when I open the browser all 20~ tabs (except a couple) are gone and don’t show in recent tabs. The few that show seem to be randomly selected. My history itself apart from that seems intact. My few remaining tabs were also in a bunch of groups even though I never use groups.
How can I retrieve my lost tabs?
Brave Version( check About Brave):
1.85.120, from f-droid
Mobile Device details
Samsung s24+, onui 8, android 16
Update: This is very interesting, after updating app to 1.86.140, all my lost tabs came back 
Application version Brave 1.86.140, Chromium 144.0.7559.76
Operating system Android 16; Build/BP2A.250605.031.A3
Samsung s23+
Same issue happened to me, my browser become bipolar. Sometimes it gives me a different piece of open tabs( since the losing all the tabs), and my old tabs also appear sometimes. It’s just weird like using 2 different browser but same history and more. Idk
The trigger might be Leo ai. It occurred again after asking Leo ai to summarize a pdf and it froze and i forced to exit the app. After that, app is in the different open tabs.