1. Open the phone settings-Language and input (language and keyboard)-Click the gear icon-Slide to the bottom-Click Reset Settings to try.
2. If you use a third-party input method, you can uninstall the software to download other versions or try other input methods.
3. If it still hasn't been solved, you can back up your important data and try to restore your mobile phone to factory settings.
If the problem still exists, it is recommended that you take the machine, purchase invoice and warranty card to the local Samsung after-sales service center for testing.