What does "Alert" mean on USPS Tracking?

On USPS tracking, the "Alert" message means that some problem has arisen which will delay the shipment of your package. In these cases, USPS encourages customers to call their support line 1-800-ASK-USPS for more information. 

Remember, the effects of COVID-19 have caused major slowdown with USPS. Tracking info is sometimes not updated at all. With this in mind, remember that in the event that something is delaying your package, you might not always be updated. Sometimes tracking info is even updated incorrectly. Keep this in mind when checking your tracking info.