I have iPhone one 7. Today, I got a call from my friend but instead of the saved name (yes, his number was saved in my contacts) his number was displayed. So, after talking to him I tried checking why the name was not displayed, I found that his contact was no morenot in my contacts any longer (only "Siri" found in apps).
What could be the reason? Is there any chance that I got something malicious in my iPhone?