There’s multiple reasons that might affect sharing GPS location, some of them are external like which environment surrounds your current location (hills, tunnels, open space etc) and internal like battery level, device load and temperature, system settings and permissions. Most of them can’t be controlled.
In Web Viewer we attempt to update location every 5 seconds. It’s important to note that message on the user panel (Updated 10 sec ago) is not reflective of update frequency, instead it reflects when was the last time that location was shared. It might never even hit close to 0 second value. The closest reflection of update frequency is how often (Updated 10 sec ago) is being update and not the value it has.