@mkzpr0 I am not sure of your situation, but let me explain one thing here. When we look at Rewards, we see something like below:
The top right is estimated earnings for the month. Once the month is over, this goes back to 0 because it starts tracking for the next month.
The area where you see my 56 BAT is what we have in our custodial partner, which is Uphold for me. So I have 56 BAT in Uphold.
When the estimated earnings goes to 0 at the 1st of the month, Brave then processes those earnings and begins to send them out around the 7th of each month. Payments can take several days or as long as several weeks. You can typically track the status of payments at Ads Payout Status Update
So when you started in December, it would make sense that any earnings you had to have dropped to 0 when it became January. But then you should have received a payment for what you earned in December sometime around January 7, give or take. If you did not get this, then I would suggest you create a Rewards Support Ticket at https://support.brave.com/hc/en-us/requests/new?ticket_form_id=360001302431 to see if anyone from Brave can look into your account and help you figure out what might have happened.