After you file

I filed 2019 returns and accepted on Mar. 20th, 2020 by turbotax.  I got state refunds on March 26th, but No Fed.  Today is the last day of June, I still do not receive the 2019 Fed refund.  Amazingly, I got Stimulus check on Apr. 15th.  I wonder whether they use regular tax refund money to give out Stimulus check which is much less than 2019 return.