Welcome to iPhoneForums, tct2125!
Take a look at the text messages you receive from your friend with the Galaxy. If there's a moon icon next to the contact, you've enabled Do Not Disturb for this contact only.
To disable it, go to Messages - this contact's messages. Tap "Details" at the top right. If it looks like this:
View attachment 21798
it's enabled, disable it by sliding to the left.
Hope that helps.