Controller won’t turn on, makes quiet beeping

My Xbox Elite Wireless Controller Series 2 stopped working after sitting on the charging dock for a few weeks. Since then, the Xbox button doesn’t light up either when I press it or when the controller is charging (both with the dock and different USB-C cables). The strangest thing is that the controller makes a faint beep when I press the Xbox button or connect it to charge. Video

The original battery was very swollen, so I replaced it, but that didn’t solve the problem. The beeping and non-functionality persist, whether the battery is connected or not.

What can I do to fix this?