Has anyone had to amend their return due to unemployment?

[Mike9241]

that's a yes. some states require amending. certain credits will 

even the IRS (IR-2021-71) says in certain cases an amended return may be required

There is no need for taxpayers to file an amended return unless the calculations make the taxpayer newly eligible for additional federal credits and deductions not already included on the original tax return.

[VolvoGirl]

You can exclude up to 10,200 of unemployment unless your income is over 150,000. The IRS will recalculate your return for the new unemployment exemption if you already filed.

If you have filed, the IRS will recalculate your return for the new unemployment exemption for you. There is no need for taxpayers to file an amended return unless the calculations make the taxpayer newly eligible for additional federal credits and deductions not already included on the original tax return.

See this new IRS May 14, 2021
https://www.irs.gov/newsroom/irs-begins-correcting-tax-returns-for-unemployment-compensation-income-...

You may need to amend your state return
https://ttlc.intuit.com/community/state-taxes/help/do-i-need-to-amend-my-state-return/00/2134732

You can log back in or open your return and it should automatically update your return and show you the new refund. But the updated return won't be sent. The IRS will adjust it for you. You may need to update the Desktop program for it.