If you printed, signed, dated and mailed the amended tax return, Form 1040X, to the IRS it will take quite a while for the IRS to process the amended tax return.
The IRS has not processed paper tax returns for several months due to the pandemic and limited staffing at the IRS. They have only recently started to process approximately 11 million paper returns in the order received.
See this IRS website for information - https://www.irs.gov/newsroom/irs-operations-during-covid-19-mission-critical-functions-continue
We’re experiencing delays in processing paper tax returns due to limited staffing. If you already filed a paper return, we will process it in the order we received it.
Do not file a second tax return or contact the IRS about the status of your return.
Go to this IRS website for the status of an amended federal tax return - https://www.irs.gov/filing/wheres-my-amended-return
