ipad pro 10.5 looses charge even while plugged in power

Hi. I have a 10.5 Ipad Pro, less than a year. I’m using an Anker Atom PD1 charger with an Anker Powerline + III cable. I noticed times where my Ipad Pro will charge, then even while the Battery Indicator says it’s charging, it’s actually loosing charge. Example from 92%(charging), it will go to 91, then 90, then 89 and so on. There was also an instance where I left it charging at 60%, I went out, and when I returned after an hour, it’s still stuck on 60%. I also tried using an Apple 18watt charger with Apple lightning to usb c cable with similar results. Any one encountered the same issue?