Once you reach 1,000 points and claim the grand prize, completing additional tasks will no longer affect the reward bar. Tasks may still be available, but they won’t add any more points until the next cycle.
However, you can still earn regular coins and various small rewards, such as items for the furnace, by completing the remaining Daily Tasks.

The reward bar resets every 7 days. In the new cycle, you’ll have the chance to start earning points again from zero. You can see the time remaining until the reset at the top of the screen.