iPad makes charging ding only when using facebook

I’ve had my iPad Pro for a few years now with zero problems. A few months back I started to notice my iPad would make the ding that it makes when you plug in the charger although no charger is plugged in. This happened quite frequently. The last few weeks I’ve taken a break from social media and like magic, the sound stopped happening. I just started using Facebook again the other day and it’s constant again. Facebook updates by itself so I don’t have an old version. Why is this happening and only when on Facebook?