When to Amend 2020 Return

I filed my 2020 state and federal tax return in February.  I owed $600 on the federal and I was suppose to get a $2000 refund from the state of California. 

 

I have not received my refund from the state yet so I called the FTB.  They said there was an error on my return.  They said my tax withholdings was higher than what they calculated by about $4K resulting in a tax due the state of $2,100. 

 

I double checked and they were correct.  Somehow I downloaded my 1099R from Schwab twice and Turbo Tax added the withholding twice ($4K).  But then I realized Turbo Tax also added the 1099R income of $45K twice. 

 

So after I deleted the second Schwab amounts, Turbo Tax shows I am should get a refund from the federal and state.  The question is when should I submit the amended returns now or later.  I have not paid the federal taxes yet.  I only filed the return.