How many times an overtime is given in FrontLine?

If Im remembering correctly, in some of the previous updates, in FL, there would be an overtime if there is at least 1 tank in one of the cap circles no matter how many times an overtime is given.

And even more former version, the time left from the overtime would be added to the time you earned from capturing a zone, like If I was inside the cap and lets say 60 secs needed to cap the zone, but overtime gives 90 secs, that extra 30 secs will be added to 2 minutes we get from capturing. But,

In the current version, It didn't give us overtime for 3rd time or 4th time, I can't remember. Is it the rules of the FL or a bug? Because I couldn't find the section that gives information about how many times the overtime will be given.