Hi L-Apple132,
Welcome to Apple Support Communities. I understand that when you type to search in Safari you're seeing the text auto-delete after the first few letters, specifically when you use words that start with "sc". I can see why you'd reach out about this behavior; I'd like to help. First, if you haven't already, try these steps:
- Quit Safari: Quit apps on Mac
- Restart the Mac.
- Open Safari while holding the Shift key.
- Try searching again.
I'd also recommend verifying that there aren't any preferences set that could contribute to this behavior: Change Keyboard preferences on Mac
If the issue persists, use these steps to start your Mac in safe mode and test for the behavior: How to use safe mode on your Mac
If the behavior seems resolved in safe mode, restart the Mac normally and test again. If the issue persists in safe mode, use these steps to test for the behavior in a new user account: How to test an issue in another user account on your Mac
Let me know what you find.
Best Regards.