Cursor struggling with simple edits

[Margarida_Carvalhosa]

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

Over the previous weeks I’ve struggled with Cursor (using Claude 4 Sonnet) behaving pretty strangely. Stuff that used to be straightforward has suddenly become a struggle.

For example, I asked it to remove all print statements from a ~7000 line folder (which were created out of the blue since we were always using logs). Instead of just removing them, it commented them out and left if/for blocks incomplete. When I clarified, it deleted them but left orphaned f-strings. I had to try multiple times, and even then some prints always slipped through. A couple times it even added new prints in unrelated prompts. I set up a Project Rules file saying not to add any print statements and referenced it often, but it didn’t always respect it.

I’ve had similar issues with iterrows - I’ve asked repeatedly to remove/replace it, but the code either comes back incomplete or it reintroduces iterrows later. Another example of issues faced was when renaming files, despite calling out on the prompt to update import statements accordingly, that was almost always overlooked and additionally, instead of the files being renamed, often a file with the new name was created and then the code copy pasted into it while not deleting the old file.

For context, I had a bigger folder open (7k-line algo I’m working on + a 34k-line algo I’m referencing) but in chats I was careful to only point it at the relevant files so for sure the context provided was always much narrower, but Cursor still felt like it was getting lost. What’s odd is that just a week earlier it was handling more complex logic fine, with only about 5k fewer lines of code. I even tried moving everything into a clean folder with just the 7k-line algo and the same issues kept happening. I thought maybe it was my flaky network, but I also tested on mobile data and saw the same behavior.

Do you have any recommendations? Would really appreciate any guidance so I can continue using Cursor in the future without having to constantly debug after simple edits or recover past versions. I have pivoted to a different project this week and so I’m not sure if the issues would persist, but they were happening during the weeks of 9/8/2025 and 9/15/2025.

Steps to Reproduce

• Work with a larger project (~7k lines in the active subfolder, ~34k lines in another referenced subfolder, both open in Cursor)
• Prompt the model to remove all print statements
• Prompt it to replace/remove iterrows
• Prompt it to rename files and update import statements accordingly

In my case, the model consistently left behind orphaned code, incomplete changes, or reintroduced patterns I had explicitly asked it not to use.

Expected Behavior

Cursor should cleanly remove print statements and iterrows when asked, respect Project Rules (like “no print statements”), and update imports properly when files are renamed. Ideally, it shouldn’t regress by reintroducing patterns or duplicating files

Operating System

Windows 10/11

Current Cursor Version (Menu → About Cursor → Copy)

Version: 1.6.45 (was update somewhere over the past 2 weeks but issues persisted in both versions)
VSCode Version: 1.99.3

For AI issues: which model did you use?

Sonnet 4

For AI issues: add Request ID with privacy disabled

6dda7f45-5c32-4833-85c1-0da23bd1f7f2

69822863-6cbb-47f9-9126-9616d205a89c

Does this stop you from using Cursor

Sometimes - I can sometimes use Cursor

[Kroka (My Name Jan)]

I’ve had about the same experience.
It honestly makes it maddening to work with Cursor for me, because the instability makes it so that I’m genuinely not sure if I’m saving or losing time in the end.

The problem is that when you have a expected behavior and quality, based on recent result (let’s say a week or so), and then suddenly have a significant slip in output quality.

Ideally, you would of course instantly recognize that stuff ain’t going as smoothly as you would expect, and shift away from using Cursor until the quality stabilized - however, that ain’t that easy. I’ve multiple times found myself spiraling down a pit of frustration just trying to perform the most basic of tasks before I can realize what is happening.

So not only do I lose productivity from the drop in quality,
I also lose it from trying to adjust to make it work as expected,
and then I lose additional from the frustration of having lost time doing so,
and finally from transitioning away from Cursor until quality improves, because disrupting the workflow and checking results is also a time loss.

This can even occur on a intraday basis, when it will work flawlessly in the morning only to become incapable of doing anything later that day.

The final time loss comes from checking the cursor forum, only to be met with the standard “We are looking into it” or “The team have been notified” when they are, in fact, not really looking into it - nor will they provide any kind of status, information or resolution to the matter.

Best solution I’ve found is simply a Three-Strikes system that whenever I don’t get the expected result after 3 tries I just don’t use cursor at all for the rest of the day - even though that in itself is completely ridiculous for something expected to be used productively.

Don’t expect them to fix anything.

[sanjeed5 (Sanjeed)]

Thanks for the detailed report, @Margarida_Carvalhosa. I can see how frustrating this is - having AI make incomplete changes and ignore explicit instructions really disrupts workflow.

Others have reported similar issues with AI reliability on larger codebases. A few things that might help:

Project Rules:

• If your rules are set to “Apply Intelligently,” they may not attach reliably. As Dan from Cursor explained here that models can fail to pick rules and too many instructions cause them to miss things.
• Try: Set key rules (like “no print statements”) to “Always Apply” and keep them short and precise.

Also try:

• Create new focused chats for each task
• You can also try other models which might do better.
• Add the 34k reference folder to .cursorignore if AI doesn’t need to edit it

Let me know if any of these help!