I just asked #CoPilot to correct spelling and grammar mistakes and to suggest improvements in an English text.
I looked at the result and could see any changes.
I asked CoPilot to highlight the changes. It did. 11 of them.
I checked again. It turned out 9 of the 11 instances were no changes or corrections (one was a spelling correction, and one was inserting the full name of a person).
This #LLM stuff seems to get worse even for my simple glorious autocomplete task 馃が