stop Live corners assumptions
When drawing with the curvature, I haven't tested with regular pen, if you draw a mix of corners and somewhat curved surfaces, then you go back to add some nice radiused corners, you will likely be annoyed by illustrator Thinking that you intended to draw a giant chamfer.
No, I didn't draw a large chamfer. Do not assume I drew a large chamfer. Assuming a radius when illustrator sees a tangent arc connecting two lines is Great. But with chamfer there's nothing to be tangent to. So just because I drew two sharp corners in a row, before two curved segments, doesn't mean that I wanted it to be a chamfer!!!!
I'm trying to create some somewhat technical drawings in illustrator. If you compare it to Some other software (not going to say which ones) the experience is Terrible. Adding live corners was great. I had to use a plugin to do that before, and it wasn't live. I had to select a corner, run the script, hit undo. I don't need it often, so can't pay for Astute graphics.
I looked through here: https://helpx.adobe.com/illustrator/using/reshape-with-live-corners.html
And there's no solution to this, sort of.
The workaround is, when you find a chamfer that you didn't want, get the direct select tool and nudge one of the corners. That breaks the chamfer that you "wanted."
This should not be happening. Seems like a bug. The corner should not become a chamfer unless you do an Option-click on the live corner widget. Could you please share more details on when this happens?
Andy Engelkemier commented
I agree, it shouldn't be happening.
It's Really easy to replicate. This example is probably what someone intended, but it's still kind of wrong.
Draw a rectangle with the curvature tool. So you'll be holding Alt (I think that's option on mac?) to make only corners rather than curves.
On one of the corners, estimate what you think a 45 degree chamfer would look like. Don't use snaps though. So there's No way you actually got it a perfect 45 degree right?
Ok, now go to the direct select tool. You'll notice that you have a single point on that corner. Yup, it's defined as a chamfer. And as soon as you touch it, your shape changes. You didn't draw that at a perfect bisecting angle, but illustrator is making the assumption for you.
In this example, that result is Usually what you might want. Now that you know what it's doing, try some other more complex shapes to see where else it does this. It may surprise you in very unpleasant ways.