I have kde connect 0.8 on kubuntu 14.04 lts, after installing android app version 1.6.2 on Android 4.4 device becomes unreachable (no ping) and cannot see other devices (refreshing device list on the phone shows no results). Downgrading to 1.6.1 resolves the issue.
Please update KDE Connect 0.8. It hasn't been supported for years. We try to ensure compatibility with older devices but we can't have everything.