iMessage delivering despite not saying "Delivered" and then resent as texts

I'm having trouble with sending iMessages to family members (same plan).

Every time I send a text it's blue but it never says "Delivered." However, it is delivered and they can see it on their phone! About 2 minutes later the iMessages turn green and are resent as text messages. My family members then receive all of my texts again at this point.

They aren't having any trouble with anyone else and neither am I.