It's not clear (at least not to me) from your info if you are trying to move old data files for 2019, 2020 and 2021 from standalone to network or if you switched from standalone to network back in 2019. 

To pull EF acknowledgments for 2020 returns - go to EF Center   select returns you need acknowledgments for    then select E-File>Electronic Filing>Update Acknowledgment Status of selected returns