Balance due returns are at the very back of the line for processing as the understaffed and over tasked IRS work on processing returns with refunds on them and putting out stimulus & advance CTC payments first.
When it comes to balance due returns, if you have timely filed and paid the balance due then it is immaterial as to when the return actually gets processed and archived for you to see in the online account. If they find something wrong you will get a notice in the mail ... so the old adage "no news is good news" applies here.
