Thank you for your reply. I have filed 2020 tax in May in which I payed an additional ~$7000 with the tax filing. I did owe IRS ~$400 and didn't notice it until recently. It is because I haven't checked my mail in a while due to international travels. In my mails, there are a bunch of notice from IRS telling me I am owing $400 dating back to June. Then one day in October, a mail came in saying I owe $100,000+ (I payed this amount in Feburary directly to IRS before filing as "estimated tax"). I am super surprised. Did IRS just revoke my entire tax return because I have owing $400 for too long?
