Question on Lipo Rider Plus BAT

I’m just getting started with the Lipo Rider Plus I ordered. I’ve noticed the battery (LP503562 1200mAh) drains quickly after the second time using it, so I connected a multimeter to check the battery voltage. If the USB-C is connected, it shows 3 lights with the 4th blinking. And the multimeter on BAT/GND reads 4.2V, which I would expect. If I disconnect the USB-C, the BAT terminal immediately drops to 3.0V which I did not expect. Is this normal?

Is the battery in need of some maintenance? Is there a way to vary the charge rate to recondition the battery or perform a near complete discharge (I know full or oover discharge is bad)