I just found this answer of a BAT Team member. So if you just restore the wallet in the same browser you should be fine, however I would not try it and I don’t think it would help.
Again, most of these cases resolve themselves. Meanwhile the BAT/Brave team is probably working on a solution for the unreliable pending rewards information.
As long as you didn’t cause any damage to the files associated to your BAT profile, I don’t think your rewards are lost. Just check the estimated rewards again after another restart of the browser or even your computer, and after some time has passed.