When the message is blue it means you’re using iMessage. The message now is green, meaning the receiver either turned off iMessage, or doesn’t have an iPhone. All I know is that when you’re blocked using iMessage the “Delivered” text won’t show.
If it was blocked tgen it won't say sent. Then it would give an exclamation mark or something. Dont really know this issue though. Try sending a screenshot to apple helpcentre
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