When I try to create a feature using an arc segment, only if the arc is shallow, as soon as I finish the arc or type in a large radius, the arc displays as a line. It is still an arc segment as it gives the option to change to a straight segment. Why won't it display as an arc? If I edit the vertices it only allows me to make the arc so shallow, then it automatically snaps to the line segment midpoint.
I have been struggling with this same problem for about a month. I just wanted to mention that a "repair" on my ArcMap (10.7) installation has fixed the issue for me, at least for now. So that may be an option if anybody else runs into this problem.