I'm new to Blender and I'm following a video on how to model a female anime body, all was going great, but when I tried to use the knife tool I started having problems.

First off the knife tool doesn't clip to the corners (corner points*) for some reason (or to the lines I want them to clip to).

Second, when I select where I want to cut it, it adds an extra cutting point. (for example if I select the corner or just a bit under the corner it would add a 3rd point alot higher, making an almost finished triangle or an A without the horizontal line in the middle).

I select where I want to cut.

This is the line it shows, as you can see I couldn't clip to the corners or it clipped to something else.

This is the result of it, as you can see it adds an extra cut above where I clicked.

https://mega.nz/file/ig5CEawI#rrSSvu9bBXjJDcEVydpAe5O1HnXx1UgIfGuR85VywNo

I can't reproduce the extra cut shown as a line and a dot, but you can see that it makes the cut alot higher than where I selected it. (Or it still does but doesn't show)

If I put the cutting point under the corner it does the exact same.

I use Blender version 3.5.1 from Steam.

I want to make a belly button and I want to make quads from the belly button as I heard it was easier to model with quads.

Am I doing something wrong, is my file corrupted or is the tool just bugged?