Endicia labels showing as counterfeit on usps site?

Today i printed a bunch of labels through my fulfillment software which uses my endicia account. I post-dated them for Tuesday 1/16 (day after the MLK holiday).

One of my customers emailed me to tell me they received an email from USPS saying there was a problem with the postage on her order. I checked all my tracking numbers from today’s packages on the official usps site and it’s saying they are all counterfeit tracking numbers.

Not sure if this is a usps problem or somehow because i post-dated them for after the holiday. Anyone else having this issue?