When your iPhone sends incoming calls directly to voicemail or is disconnected after a ring, it might be due to various reasons. This can occur if the recipient's phone is powered off, in a low signal area, or if they have enabled the "Do Not Disturb" mode. Additionally, the contact's number may be blocked or marked as spam.

Understanding the Context

So, hold it right there, and refer to this link: If you Forgot the Passcode on your iPhone, or your iPhone is Disabled - Apple Support. It would be the one you've always entered.