I kept open tabs as "bookmarks" (foolishly: (for several months, there were about 200 of them, yesterday I opened opera v.54 (Android) and saw instead of [...] tabs only [1] they were all reset, search in the history did not help, and it is incomplete, it's a pity for me 
It was such an interesting and important data. Maybe there is something in the phone's memory ? I did not clear the cookies and cache. I would be very grateful for help,