A bug i had.

Yesterday, i was playing against someone in the endgame and it was my opponents last limbs like 3 seconds but then the timer increased by 10-15 seconds and that kept happening until a few minutes later.

What happened?

you were probably playing a game where every time you move you get more seconds. that is kinda common.

the seconds didn't increase for me

It depends on how quickly you were inputting your moves.

i made my move so fast but my time didn't increase

Can you send the link to the game?

I think it's in settings, but that person might've been cheating.

I couldn't find it.

Can you tell me your opponents names like yours is 
RwandaChessMaster