It’s always dangerous to follow the instructions, but what Oregon tells you is:

“Enter the tax rebate (economic stimulus payment) you received from the federal government in 2020 [emphasis added] plus your recovery rebate credit, if any (Form 1040 or 1040- SR, line 30).”

This amount is subtracted from 2020 actual tax, so it reduces the federal tax deduction (FTD).

So if EIP#2 was not received, it will result in a recovery rebate credit, and a lower FTD.

If it was received, it would have been in 2021, not in 2020, so there is nowhere it needs to be entered.

Isn’t this what you are saying the program does? If so, where is the error? Always remember, don’t expect taxes to be logical.