Estate Taxes / Interest money earned from the IRS

The deceased passed away in 2012 and an estate tax return was not filed until 2018 and 2019. Money was paid ahead to the IRS upon learning this that way there would be no additional penalties. The reason 2 years of tax returns were filed is because it took some time to find all the assets that the deceased owned and money was found and collected over the course of 2 years. Last year, the final return was filed thinking we were done with the estate. A refund was then received in 2020 from the IRS for the over payment, plus money that was due back as a refund on the return. An Interest statement 10-99INT was received from the Department of Treasury for $86.33 for 2020 for the interest that was earned on the estate. Do I have to file another tax return for the estate for 2020?