Got “Final Balance Due Reminder – Notice Of Intent To Seize Your Property” for balance I already paid

Sorry to make another "Should I be worried?" thread, but I am kind of losing my mind here.

A quick rundown of my situation:

• Erroneously received the unclaimed $1400 stimulus check from 2021 last December (filed a 1040NR in 2021, so I wasn't eligible for that).
• Got the letter in July telling me to pay it back.
• Called to verify and was told to wait for another communication from the IRS, because I might not be required to pay that after all.
• Never heard back, so in December 11th, I called to check if the balance was still there, checked my 2021 transcript, and there was a balance of $1485 on my account.
• On December 11th, I made a payment of $1485.
• Transcript for 2021 updates a couple days later, now showing a -$3.00 balance and the payment I made on the 11th. Tax compliance report still says "noncompliant" and shows a $1485 balance.
• Called again to ask when that payment would be reflected in my records, person on the phone said it would be two weeks, so likely they wouldn't be able to see it until the 26th, but otherwise there's nothing else of note in my account.
• Next week I get a notice from the post office that there's inbound mail from the IRS, set to arrive on the 22nd. Ends up arriving on the 26th due to Christmas and needing a signature.
• On December 22nd I checked my mail and there's a notice CP504 in the mail for tax year 2021, postmarked on December 22nd, telling me to pay the balance immediately or my assets will be seized if payment is not received. The same notice is also visible on my IRS.gov account.
• However, the tax compliant report now says "Compliance issue", but there is no balance due on there, the transcript still reads a negative balance of 3 dollars and still shows my payment on the 11th. All other tax years show a balance of $0.
• Tried to get on the phone with someone to verify if I'm in any trouble, but the lines are down due to Christmas.

My assumption here is that the notice was sent before the IRS could see that I had made the payment on their end (before it "went through", so to speak) and so I have nothing to worry about – I paid the amount that was listed. However, I am left with two things I am not clear about that are giving me some concern:

1. The letter was postmarked for the 22nd, but the payment I made was on the 11th. Is there any chance that there might be something else I must pay that I am not aware of, or that I am being penalized despite already having made the payment?

2. What exactly does it mean for the tax compliance report to show "Compliance issue" with "possible compliance issue" underneath? Is this something that I should be concerned about, or is it just reflective of there having been an issue previously?

3. In short terms – should I be worried, or am I in the clear since I paid that balance off before the notice was sent?