If you get on the center wall (the one between the two circled edges and due west of the hive) as skulk, and try to walk over one of the circled edges, it is easy to have your movement blocked. This does not happen if you have substantial vertical movement while rounding the corner, and seems to happen more often when moving slowly. A method that seemed to give me good results for reproducibility is to get vertically level with the bridges, and try to move due north (not up or down at all) around the corner. It acts as if there is an invisible wall blocking you from moving around the edge.
I never had this problem in beta 5, and attempts to reproduce this error in beta 5 failed.
I am not certain if the problem existed in 3.0 final, but I know it exists in 3.0.2, and there were no documented changes to the map between the two versions.
There are many similar corners in maintenance. Some of them exhibit this behavior, some do not.