M2 12.9” iPad Pro charging slowly

Normally my iPad used to charge within 2 hours. Last week I had to go out and it slipped my mind to unplug it, so, it remained connected to power for 8 hours 😕. Ever since it takes at least 4 - 6 hours to charge. I’ve tried to remove something like optimized battery charging from iPhone but it seems like it doesn’t exist on iPad. So, how do I get my fully charging speed back? PS: I use the 35 W adapter and the original cable.