Whatsapp does not show a contact. Tried "everything"
Some options you could try:

Option 1

Tap on  icon and then go to  Menu &gt; Refresh.

Option 2

Tap on  icon and then go to  Menu &gt; Help. There are some instructions their which you can try and tap on Show invisible contacts.

Option 3

Follow this article from WhatsApp to try to troubleshoot: How do I add contacts to WhatsApp?