Mailed Tax Return Status Unavailable

It is taking the IRS months before they start to process mailed 2020 tax returns.

The IRS is seriously behind in processing 2020 tax returns.  This is due to many factors, such as the pandemic, completing processing of millions of 2019 tax returns, stimulus payments, unemployment compensation exclusion tax refunds., changes in the tax code by Congress in the middle of the 2020 tax season and the like.

Millions of taxpayers have not yet received there federal tax refunds.

Go to this IRS website for operational status - https://www.irs.gov/newsroom/irs-operations-during-covid-19-mission-critical-functions-continue

As of June 23, 2021, we had 17.5 million unprocessed individual returns in the pipeline. Unprocessed returns include tax year 2020 returns such as those requiring correction to the Recovery Rebate Credit amount or validation of 2019 income used to figure the Earned Income Tax Credit (EITC) and Additional Child Tax Credit (ACTC). This work does not require us to correspond with taxpayers but does require special handling by an IRS employee so, in these instances, it is taking the IRS more than 21 days to issue any related refund. If, as a result, a correction is made to any RRC, EITC or ACTC claimed on the return, the IRS will send taxpayers an explanation. Taxpayers are encouraged to continue to check Where’s My Refund? for their personalized refund status and can review Tax Season Refund Frequently Asked Questions.

I would suggest that if in future years you mail your return you use a method where you get proof of delivery.  The USPS was also severely impacted by Covid.  sad to say but in (Chicago area) newspapers and on public broadcast news stations there have been reports of postal workers throwing mail in the garbage.