Calls go straight to voicemail after one ring or no ring
Text messages stay as green bubbles if they were normally blue before
iMessage texts show as sent but never show Delivered
FaceTime calls do not connect
You cannot see their profile photo or updates in Messages if they used to appear
Their phone status seems unavailable when you try to contact them
You can still call or message from another number and it works
Their contact card may appear unchanged, but your messages never get a response
They are missing from shared location or sharing features if they previously shared them