Hi, I am sorry you are having difficulties sending texts. The app could just need simple maintenance. Having trouble with unresponsive apps? It may be time to give them a good spring cleaning. Don't worry, you don't have to uninstall the app or reset your phone. Instead, clear the app's cache or data. When you do this, any problematic files or bugs in the app will be deleted. You can also use your phone's Device Care features to limit background apps and help your battery last longer. Try these steps here: https://www.samsung.com/us/support/answer/ANS00077611/
Next, you can try resetting your network settings with the steps provided earlier:
Settings > General Management > Reset > Reset Network settings
Another thing to try is wiping your device's cache partition. The steps are:
Performing a wipe cache partition removes any temporary files that may be causing an issue with the device. All personal files and settings are not affected by this option.
- Ensure the device is powered off.
If the device is unresponsive/frozen, press and hold the Power button (located on the upper-left edge) for approximately 10 seconds or until the device power cycles.
- Press and hold the Volume Up button (located on the upper-left edge) and the Home button (located at the bottom in the middle).
- While continuing to hold the Home and Volume Up buttons, press and hold the Power button (located on the right edge) until "RECOVERY BOOTING" appears in the upper left then release all buttons.
- Select wipe cache partition.
Utilize the Volume Up/Down buttons to highlight and the Power button to select.
- Select reboot system now.
Option is highlighted, utilize the Power button to select.
Finally, you can see if a third-party application might be responsible. The steps for Safe Mode are here: https://www.samsung.com/us/support/answer/ANS00062983/
If all the troubleshooting has been tried, reach out to your carrier for further assistance. Please let me know if this helps.