As explained to me by those more adept than I am in the programming area of EL:
More than likely, its due to time gap between each "client check". Your tracker client feeds data to the EL server live (which is why you can almost instantly see globals on EL after they've been tracked).
The server however, needs to make intermittent checks to the clients for the "# of clients online", otherwise that additional data processing would put a lot of demand on the server, the client, and your PC (causing lag and annoyances all around).
Example:
1:00 MA time, 6 clients are verified by the server as online, EL shows 6 clients for 10 minutes.
1:02 MA time, 1 client logs off (now 5 clients active)
1:04 MA time, 1 user flys off planet (now 4 clients active)
1:06 MA time, you get a global (not reported due to minimum reporting not being met)
1:07 MA time, you check EL and see no global, and 6 active still
1:08 MA time, 1 client logs back in (5 active)
1:10 MA time, 1 person flys into planet (6 active) EL checks, yup 6 active, shows on EL
1:12 MA time, you check for your global again, no global, and still EL shows 6 clients (WTF where's my global??)
What you see on the front end, is 6 active clients the whole time, what EL server sees is this ^^.
Hope that helps to explain this issue, when the client count is right on the line like that, it just takes 1 or 2 clients disconnecting briefly to go from "all globals tracking nicely" to "wtf? where did those last 2 globals go?
Simple solution is more clients so there's extra to cover the logoffs, crashes, etc. We'll look into other options of optimizing the situation as well.