Ensure emptying 'Recently Deleted' succeeds?
Here's what I did
Go into Photos -&gt; Recently Deleted
Click 'Select' (top right)
Slide your finger from the photo at the very bottom of the screen up to the top of screen (without lifting your finger), this should select everything on the screen, and now hold your finger at the top of the screen until all the photos in Recently Deleted have been selected, then press 'Delete'
Tip: if you have a lot of photos to delete, before doing the above, press on the three dots (...) on the top right and zoom out, that will allow you to select more photos per minute.
Note: for 25000 items, this took approximately 9 minutes.