The applicable window is the three tax years preceding the one for which abatement is requested.  What year is involved here?  Little early for 2024 so probably 2023, and you have to go back to the Covid year of 2020.  Do you have transcripts for 2020 through 2022, or are you relying on the taxpayer's memory?

It may have been that the IRS phone assistor's IDRS was down and it was not possible to check the history in real time.  That's why a written request is more likely to succeed. It only takes a paragraph and a postage stamp.