Not a bug

When selecting text using touchscreen, an attached keyboard cannot do anything with it

Tim Burgan 5 years ago in iPad updated by Alexander Blach (Developer) 5 years ago 2
When I select text using my finger and i have a keyboard attached via bluetooth, I cannot then expand/contract the selection using the keyboard. Also, I cannot put the delete key on the keyboard to delete the contents of that selection.
Under review
You need to do a single tap on the editor once, so that it has focus. Only then can you use the external keyboard cursor keys to modify the selection or use the delete key to delete the contents.

If you are using the default settings, the row of additional keys comes up when it has focus.