Federal Taxes: Tax Lien Even Though Payment Setup

I received a letter from the IRS stating they issued a tax lien due to past due tax amount. The amount owed is a little over 50k. However months ago I called and talked to them directly and they agreed to setup a payment plan. I been paying my monthly amount on time. So Im confused about the tax lien, is it because it is the amount I owe is so high? Also how does this affect my earnings and my property/bank accounts? Will they seize that going forward or is that only a levy? I dunno what else to do, I setup a payment plan.

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I also want to point out originally the IRS sent me a letter explaining that they would file a tax lien if I dont pay, but this was after I called to make a payment plan. Soon after I received another letter stating that they had sent the initial letter in error and that no action was needed on my account. Could this mean they filed the tax lien by accident not knowing I had a payment plan already setup?

Federal Taxes: Tax Lien Even Though Payment Setup