I'm thinking the same thing. The CCR was paid a little while back at the end of January or early Feb I think we received ours but we got our Rudd bonus of $900 today.
it's possible it's your dec quarter payment as it's processed over a three month period

if you get ftbb and you were due ftb today you may have gotten some Krudd money on top of ftb

you'll get a letter in a few days to explain