My phone is not sounding when I receive texts

This is why I asked the poster above you if they wore Apple Watch? If you wear Apple Watch, notifications will come to your watch when your iPhone screen is inactive. Notifications come to one or the other, but NOT both and this is by design.

Read this to better understand how notifications work with Apple Watch --> About notifications - Apple Support

See this at the top of that document:

Where notifications appear

Notifications appear on your Apple Watch or iPhone, but not both.

You can change whether or not you’re notified about messages you receive in the Messages app  and how they appear or sound.

For example, you can turn off message notifications so you aren’t distracted by notification sounds when you’re in class or other quiet settings,

or

assign a special sound for certain contacts so you know when you get a message from them.

See: Change message notifications on iPhone - Apple Support

Do you wear Apple Watch?

Mine either.... I'm missing every text unless I'm looking at the messages on phone. I've changed volume and tones to the loudest I can, and my iWatch is not on Do Not Disturb.