Please try the following:
# Reset your phone's network settings. Open the settings app and type "Reset network settings" in the search box. Follow the prompts to erase the settings. Afterward, you will need to re-enter your WiFi password and re-pair any Bluetooth devices.
# Uninstall/reinstall your text message app, or use Google's Message app at [link|https://play.google.com/store/apps/details?id=com.google.android.apps.messaging|https://play.google.com/store/apps/details?id=com.google.android.apps.messaging|new_window=true]