The time is wrong

So I noticed playing in the arena playing 3m time control and 6 minutes left for the arena. When I lost, my time was almost up and so was the arena's time, but my opponent still had about 1 minute left. So I started another one with 59:30minutes left. The game was done with 53minutes left, so 6:30minutes passed and we still had a combined time of about half a minute left on our clocks.

Is there some sort of increment even when there is none? something to balance out lag? Because shouldn't a 3m time control last no longer than 6minutes? Because otherwise it means with 6:01 minutes left for the arena, it might get aborted because the arena has ended while you're still playing when at least one player should have lost on time before that if not checkmated earlier.

i cant understand what are you saying

the server refunds lag time every move (i.e. go to the top bullet game and watch only the clocks. sometimes the time may go from 55 seconds to 56 even if the game has no increment)

TL;DR: the time control was 3 minutes, but the actual game lasted 6:30minutes with my opponent still having 1minute left, even though that shouldn't be possible. I timed one just now and there is an excess of 13seconds, so not as severe.
Ok, just wanted to make sure it's intentional

ok

then report it as report a bug

go to help and report it

it's not a bug

the server lags some and so you get automatically refunded

its true

its totally true

i had a bug in four player chess

Total time = time used on player A's clock + time used on player B's clock + time used to communicate updates between the two players, perhaps.

i dont understand

I think what they're saying is, it will give you extra time if you have lost time from lag, so sometimes a 3 minute game can go longer than 6 minutes.

what???