We have identified the issue and have updated our systems to respond to Sprint's erroneous spam blocking. We are monitoring the situation.
Identified · UTC
This problem is limited to customer mobile phones using Sprint Spectrum networks. We are working on a solution. Customers may not know what network they are using even if they know what carrier they are paying, so asking customers about their carrier may only cause confusion.
Investigating · UTC
We are investigating a report that Sign To Sell text messages are being blocked.