From Iqoo 13 official website (https://www.iqoo.com/en/products/iqoo-13) I got this information about bypass charging feature in Iqoo 13:

"Bypass Charging

Directly power the phone using the charger, bypassing the battery. This prevents the battery from overheating and lowers the phone temperature. It ensures a stable power supply when charging during gameplay. It also reduces the charging and discharging cycles, helping to extend the battery's life."

However, when I activate this bypass charging feature in Iqoo 13 by turning on the Direct Drive Power Supply button in game and plug the original charger & cable, the battery percentage still increase slowly (increase around 1% per 2 minutes). 

My understanding is when the battery is being bypassed, the battery will not be charged and the battery level percentage will not go up.

So how does this happen in Iqoo 13? Is it normal?

Does Iqoo 13 has different mechanism in implementing its bypass charging feature? If so, does it mean it's not a bypass charging since the battery is not being bypassed?

If it's the way the bypass charging works on the Iqoo 13, is it still safe for the longetivity of the battery to play game and still slow charging the Iqoo13 through this "bypass charging" feature?