Did you check if the database itself is empty? Sometimes the extension seems to create another. The filename of the default one is just "1", the other then would be "2" and so on. They would be in a path similar to this, depending on your OS and browser:
C:\Users\Whoever\AppData\Local\BraveSoftware\Brave-Browser\User Data\Default\databases\chrome-extension_edacconmaakjimmfgnblocblbcdcpbko_0\1
On the other hand this happened to me twice. I lost ten thousands of tabs/URLs. There's not much more than to stare into the agonizing abyss of where your tabs once have been.
Or, if you find the databases you could this:
https://github.com/rxw1/sbh A little tool that finds your databases and exports your stuff, and various other things.