My COI haplotype network includes divergent clades of a parasite species isolated from rodent hosts, but its shape is confusing and I am unsure how to interpret it. I created networks using both the TCS and median-joining methods, and both look very different. The TCS network ('tcs-network' figure attached) creates a network in the shape of a circle and the median-joining network ('mj-network' figure attached) produces many median value nodes in a 3D-like ball shape.

Each of my 9 sequences represents its own haplotype, and they are colored based on collection locality (across the state of Oregon). I am used to more linear-shaped networks, and networks without so many median nodes, and am wondering if there is any significance behind this circular representation? Or if there is a method (TCS vs. MJ) that is preferable for COI sequences, or for analyses that have differentiated individuals up to ~14%?