Error Note? (Answer Received)

Hello everyone,

Hope you all are enjoying your weekend!

I've received a bill today that I would love to know more about.

Is this an error? Insufficient ink?

At first, I thought this was due to age, but then again the ink shown on the other parts of the bills are perfectly fine, it is just the serial number and the seal on the front.

I know that they are a few reverse errors on these bills as shown here, but I am not sure about the observe of this bill.

The seal and the serial number seems to be faded, low ink, no color, etc..

I've tried doing more research on my end just now, it is really hard to find an answer or anything similar.

It's either I find the reverse bills that either been washed or an actual error (not sure with this piece), but then the observe is just fine. (this observe seems to have a fading seal and serial number)

And other examples I've seen is where the serial number and seal is completely missing, but this bill's seal and serial number is still visible, just very light and light coloring.

Wouldn't bleach or any chemical remove the entire serial number/seal completely? And the "Washington D.C." on the seal is perfectly fine without any fading.

Would love to hear from you all.

Thanks