known_hosts cannot be updated automatically via ssh and ssh-keygen

**"OpenSSH for Windows" version**
7.7.2.0
 
**Server OperatingSystem**
Any

**Client OperatingSystem**
Any

**What is failing**
ssh StrictHostKeyChecking=no user@target
ssh-keygen -H

**Expected output**
ssh automatically updates known_hosts
ssh-keygen deletes relevant entries in known_hosts

**Actual output**
known_hosts is not updated
