Brave Rewards shows I have designated over 12 Billion BAT for creators

I have never specified a donation amount, just used auto-contribute between 20 and 50 BAT monthly.
Brave Rewards shows the following (amount increasing for months):
You’ve designated 1288490318.6 BAT for creators who haven’t yet signed up to receive contributions. Your browser will keep trying to contribute until they verify, or until 90 days have passed.