Chances are, there's water leakage.
Do you use RO water filter? The machine often throw away water in the tank and replaces it. Once I measured, it filled an entire bucket from midnight to morning.

Anything that uses a floating ball may be compromised and causing water to overflow. Water tank, toilet cistern, etc.

yeah, internal pipe leak is the worst.

Enjoy it while you still can.
Eventually, they will replace with a new meter.

Haha, demmit!
That is the water dept inefficiency at work. They don't care about maintenance nor profit. I was only fortunate to enjoy a broken meter for 6 months before they replaced a new one. Here in Johor, the minimum fee is RM10.50, so consider yourself fortunate they only charge you for like a cup of coffee.