Are you on your phone? The app is problematic.
If you have a computer, try using it. I have found that to delete items now, it is best to go down the page, placing a check on those you want to delete, and then hitting delete when you get to the bottom of the page.
It used to be that you could delete each item separately, but that doesn't work well anymore, so I wonder if that is how you are trying to delete.
It could be a temporary glitch. Trying again in a few minutes might help that.
Hope this works for you, OP, I understand how frustrating that can be.
