iPad mini 4 Severe Battery Drain

I have an iPad mini 4 (WiFi only) running 14.4.2. I got a non-Apple battery replacement just over a year ago. As you can see from the screenshot below, Coconut Battery says that the battery is still at 100% charge capacity.

Recently it has started using so much battery that I get only a couple of hours of use before I have to charge it again. I generally charge it overnight, use it for a an hour or so to read the newspaper in the morning, charge it and then use it again in. the evening to read Apple News+, Flipboard, Kindle novels, etc. Usually it is down to around 20% battery left after a few hours use in the evening.

The other day, when it was fully charged in the morning, I force rebooted it, signed in and then left it idle for 24 hours. I started no apps and the screen was never on. After less than 24 hours of being idle the iPad had shut down because the battery was completely dead.

Here's what battery usage looked like during the 24 hour idle period:

I never, ever listen to music on my iPad. I have no idea where that came from.

Here's what Coconut Battery says about the battery. It seems OK, but the cycle count is way, way off.

Something is eating the battery. What could it be?