If the chat feature appears greyed out on the mobile app, clear the Android cache:
Within your phone's Settings, select App.
Click PeopleHR, then Storage.
Select Clear Cache and Clear Data.
Log out and back into PeopleHR.
If the chat feature is still greyed out, raise a case online providing the following information:
Names of users affected.
Is this affecting only iOS or only Android users?
Make, device model and operating system.
PeopleHR mobile app version.