I'm trying to draw a circle in QGIS 3 with the shape digitizing toolbar. I've tried several of the "add circle" options and they all look normal while drawing, but once I click to finish the shape it is no longer a circle. Please see the attached photo. Any ideas on how to fix this so I can create circles?
You are drawing a circle in the coordinate system of the layer. Qgis reproject that circle to the coordinate system of the project, and that figure probably no longer looks like a circle.
You need to set the coordinate system of the layer to EPSG:3721 before drawing the circle, if you want to see it like a circle in the project CRS (EPSG:3721).