I keep getting an iPad storage exceeds iClould storage capacity and iPad won't back up.

I am getting a more iCloud Storage needed message on my iPad with the details that I am storing 29.81 GB of photos and videos, exceeding the 20.87 GB of available iCloud storage. I think the issue is that I was also storing original photos on the iPad instead of optimizing storage. I turned off Photos under iCloud on the iPad, and deleted all photos from the iPad. I deleted all photos from the Recently Deleted folder. I have turned off the iPad and restarted it twice. But I am still getting this message when I try to turn the iCloud Photos back on. Not sure what I am doing wrong, or is there a need to wait a certain amount of time?