It's almost like the blockchain reset to a prior time before those rewards were sent to you or something...
I doubt it, as I don't see anyone complaining of the exact same problem and this one would be really big, as I have had some of them for months there. Not impressive amounts luckily, but still, the issue remains. That's actually the reason why I haven't moved or exchanged them for a different crypto, I thought it's too small amount and I liked BAT anyway...