IRS Newswire today, Issue IR-2021-159:

WASHINGTON – The Internal Revenue Service reported today that another 1.5 million taxpayers will receive refunds averaging more than $1,600 as it continues to adjust unemployment compensation from previously filed income tax returns....
The IRS started with the simplest tax returns and is now reviewing more complex returns. The average refund amount is higher for this round because the IRS included an adjustment to the Advance Premium Tax Credit (APTC).