This only started happening on my iPad, not on my phone:
The FaceTime icon showed a missed called yesterday, which never came.
My husband and I figured he mistakenly called me, since the log showed his number.
But I couldn't get rid of the number 1 on the icon, and then this morning, it's a number 3 but shows my husband's number again.
Now I know my husband did not use FaceTime to call me overnight, we were both asleep, lol.
And I wiped the log but I still can't get rid of the number 3 plastered on the icon.
It's not exactly a huge issue but it's annoying.