The User Presence  Properties are set to true but still the feature is not working. 

-- Your avatar on header doesnt show green dot on home page:

 

-- When two users watching same record, user presence is not visible on the header of the form:

 

-- Correct user presence property is not enabled

-- After presence property is enabled, browser cache is not cleared

1.Make sure value of the system property 'glide.ui.presence.disabled' is false:

 

2. Clear browser cache to see the change.User presence works only if the browser cache is cleared after property is enabled.

 

1. If you want to read more about why you need to flush browser cache to see the change read more about it in this article: