Your messages show as delivered but not read for a long time
Your calls go straight to voicemail or never connect
Your texts stop getting replies
You can no longer see their profile photo, status, or updates
Their online activity or last seen disappears
Your messages to them never get a response across multiple attempts
You cannot add them to a group or contact list
Their account seems unavailable or inactive to you
Mutual contacts can still reach them but you cannot
You notice sudden silence after normal communication was happening before