Question: Messaging quarter moon shape beside name on text...,,
The reason for the quarter moon shape beside a text message is because the hide alerts is turned on for that particular string of messages? Select the letter i in the upper right corner of the message then scroll down until you see hide alerts. If the button is green you will not be alerted when someone responds to that text. Turn the button off and you will resume getting alerts on that string of messages.
iPhone SE, iOS 11.2.6