Here's a fix:
Originally Posted by Grato
Yes Me too facing the same issue. Didn't find a solution either.
This is a known issue with the default launcher of Elife E7. Whenever you quit an app (by sliding it away on the homescreen), the launcher force quits the app. So, if you close WhatsApp like this, you automatically turn off the notifications.
There are two ways to solve the problem:
1) Don't ever quit WhatsApp by sliding to clear it in the Navi launcher.
2) Use another launcher, like Nova Prime or so.