The IRS was 16 million returns behind for 2019, before the May filing for 2020. But most people who efiled and had no issues did get their returns. I suggest you contact the IRS and ask if they explain why you have not received a refund.
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
The IRS is opening mail within normal timeframes and all paper and electronic individual returns received prior to April 2021 have been processed if the return had no errors or did not require further review. As of August 6, 2021, we had 12.7 million unprocessed individual returns. Unprocessed individual 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 and in some cases this work could take 90 to 120 days. 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.
What you should do: In most instances, no further action is needed but you may check Where’s my refund or you can view your account. If you filed electronically and received an acknowledgement, you do not need to take any further action other than promptly responding to any requests for information. If you filed on paper, check Where’s my refund? If it tells you we have received your return or are processing or reviewing it, we are processing your return, but it may be under review. We’re working hard to get through the backlog. Please don’t file a second tax return or contact the IRS about the status of your return.