Test project to understand TilemapCollider2D collisions (or for reporting a bug if there is one).
This project has been built in Unity 2020.1 and tested on macOS Catalina (10.15.7).
This repo is referenced by Unity forum question Weird behaviour on TilemapCollider2D.
Here are the strange behaviours I'm seeing. Note the contact points appear to be correct at first contact between the circle and a tile but then veer off such that they're not on either collider's edge. In some cases, they even move outside the tile they refer to.
.gif "Screengrab focusing on the circle")
.gif "Screengrab focusing on the tilemap")