Hello Tunesproblems,
Thanks for that info and for choosing the Apple Support Communities. If I understand correctly, you are unable to repeat songs in the Music app on your iPhone. If you haven't already, please force close the Music app and restart your device as iOS clears cached data and does other system optimizations when you turn your device off and on.
Force an app to close on your iPhone, iPad, or iPod touch
Restart your iPhone, iPad, or iPod touch
Play music on iPhone
Next, make sure your iPhone is up to date, as the updates contain stability fixes that can resolve issues like yours, as well as important security updates to keep your iPhone safe.
How to back up your iPhone, iPad, and iPod touch
Transfer photos and videos from your iPhone, iPad, or iPod touch
Update the iOS software on your iPhone, iPad, or iPod touch
Cheers!