Why is the app messages always freezing for 10-15 seconds before allowing me to send a text

Basically, when I open the app messages to send a message as I try to type the name of the contact I want to text, the screen freezes from 10 up to 15 secs leaving the name section blank without receiving any feedback from the keyboard. After 10 seconds the name I had typed pops up and I can continue with the procedure !

Somebody help me !