My iPad 6th Gen WI-FI had a weird battery level indicator

Recently, my iPad 6th Gen WI-FI's battery level indicator behaved weirdly. It started when I saw that the battery level was stuck at 17%, I decided to restart my device, the battery level was down to 8%, and then weirdly rised to 19%. I then let my device sit for a while, it now showed 15%. After that, it went back to normal. The analytics showed 1932 battery cycles which means around 61% battery health. I had this device since Christmas 2018.

Update: I didn’t properly plug in the charger. It dropped from 10% to 6% in 2 minutes. At first, it charged slowly, but it looks like it’s now charging fast.