Hundreds of thousands of people who were eligible still hadn’t received their third stimulus payment by last fall, according to a report by a federal watchdog agency. The report, released earlier this week by the Treasury Inspector General for Tax Administration, said nearly 645,000 people who were eligible for the $1,400 payments hadn’t received them as of Sept. 16, 2021. Those payments added up to more than $1.6 billion, it said. By that time, the Internal Revenue Service (IRS) made third stimulus payments to 167 million people, or nearly 99.5% of those eligible, it said. The IRS also issued…