Retirement tax questions

Hello @MinhT1 , your previous reply was very helpful.  Thank you very much for that.  

I received my Excess Deferral check today.  

They have broken it down into 3 parts: For argument's sake, let's say the Excess Deferral is $100.  They also returned the employer's match of $20. And then the income on the contributions which is $10.  So let's say a total of $130.

Based on your original reply, the $10 income will go on the 2021 return only.

But what about the return of the employer's match of $20?  Does that go along with the $100 Excess Deferral onto my 2020 return for a total of $120?  Or is the Employer Match not related at all as it had nothing to do with the $19500 individual contribution max?

Thank you again!

Aroon