Calls directly go to Voicemail on iPhone 15 Pro Max

1. Do Not Disturb (DND):

• Check if Do Not Disturb is on. Swipe down from the top right and look for the crescent moon icon. If it’s highlighted, tap it to turn it off.

2. Focus Modes:

• If you have a Focus mode set up (like Work), it might be silencing notifications. Go to Settings > Focus and check if any modes are enabled.

3. Silent Mode:

• Make sure your phone isn’t on silent. Check the switch on the side of your phone.

4. Check Call Settings:

• Go to Settings > Phone and ensure that Silence Unknown Callers isn’t enabled. This could be why some calls go straight to voicemail.

5. Notifications Settings:

• Go to Settings > Notifications and check if notifications for important apps (like Messages and Phone) are enabled.

6. Software Update:

• Check for any software updates. Go to Settings > General > Software Update and install any available updates.

If the problem continues, you might want to contact Apple Support for further assistance. Let me know if you need more help!

What have you done so far to troubleshoot? Anything at all? Contacted Apple Support directly or gone to your local Apple Store? Contacted your carrier? Are you connected to WiFi and using WiFi calling when this occurs? Do you have strong carrier signal when this issue happens. (Particularly the calls going straight to voicemail)? Too many possible pieces for anyone on this user to user forum to garner a real guess to what may be happening but any other details you can provide might be more helpful

Number 4 on Zaazo's list is the likely culprit. I had inadvertently toggled this on and had the same issues you are describing.