5-Year as of 2019 Data

Hi,

I was trying to pull up 5-YR Estimates as of 2019 and saw an Icon saying the data was unavailable.  I am new to ACS data and have been accessing the 2019 5-year estimates for the past year but not able to now.  Could someone provide me with a reason for the data being unavailable; does the 2021 5-YR estimates basically remove prior year 5-year ACS estimates?

Thanks