In February a display bug was reported that caused rewards panels for some users to show ‘duplicated’ tokens, or more BAT than the user had actually earned. A fix for this was released in 1.11.97 (https://github.com/brave/brave-browser/issues/9889). When you verify your wallet, or update to 1.11.97, the displayed number readjusts to its actual value.
If you have updated your browser to 1.11.97 or recently verified your wallet with Uphold and experienced a decrease in the displayed amount of BAT, please know that this was purely a display bug and No BAT has been lost.
The Brave Rewards Team