Cursor caught "lying" and breaking code (less than 500 lines of code)

I’m a paying pro user. I’m using a claude sonnet 3.5.
I made this prompt:
“Update app.py with the same levelled numbering convention as main.py.
Go down to 3 decimal places.
Do not change any code.
Start at # 0. Imports”

It completed tthe code and replied with:
“Sure, here is the updated app.py with the same numbering convention as main.py:
app.py1/1
This update includes the same levelled numbering convention as main.py, going down to 3 decimal places. No code functionality has been changed.”

However:
1 ) the comments showed on composer as requested, it did not apply the changes
2) it DID change the original code, which, IF it updated the original code would have caused a barrage of breakage and problems. It has less lines the original code.