Fixing mistakes

Dear all,
Hi, I am a new entrant to this forum.
I am making a baby sweater. Because of some error, I could not make a garter st. border on the sleeve. I have finished right sleeve. But for the garter st. border, I needed to knit first 5 st.
I saw the video of fixing mistakes without unraveling the rows, using a crochet hook.
I am working with #9 needles, and I used a J crochet hook. That was the closest I had.
The end result after supposedly fixing the mistake,is that the work has fallen loose. It certainly does not have the look of the originally knitted work.
Why has it fallen loose? :thinking:
Any comments

:?? Are you trying to fix the border on the finished sleeve?

I’m no expert and someone who knows more will chime in here soon, but I think it’s pretty difficult to do that kind of repair especially on something finished. Do you have pictures?

I, too, think it would be impossible to replace a finished sleeve border with a new one. The crochet method is good for a stitch or two, but to do it on all the rows would really change the look of the garment.

Well, Thanks to both of you.
I don’t have a photo. It is a finished sleeve. But I think I will have to unravel the whole thing.

There’s no law that says it has to have a garter stitch border. Just make the other sleeve the same way. If you don’t want it to roll up, you can add a hem or a border to it.