**BUG** Concise problem statement: Changing an existing track from one layer to another using the 'Layer' field in the 'Track Properties' box causes redundant vias to be placed where the track switches layers. These cause errors during DRC checks. Steps to reproduce bug: 1. create new pcb, place some THP pads. 2. Route a track between 2 pads, changing layers along the way 3. select a track segment and change its layer in the 'Layer' field of the 'Track Properties' box Results: additional vias have been created at existing vias or pads. These cause errors during DRC checks Expected results: no additional vias should be created, and existing vias should be automatically removed if the moved track segment is adjacent to another track segment on the same layer. Browser: Chrome