The new Junction method introduced in ArchiCAD 17 can be enabled by turning off the “legacy intersection method” found under Project Preferences > Construction Elements.
After this legacy checkbox is turned off, your models’ junctions may appear different. It is advised to review the model, make necessary amendments to the model geometry and also check for previous workarounds that may no longer be necessary (for example 2D patching or SEO).
Existing junctions that do not involve geometric element collision will not clean up automatically. If you want automatic junctions to take effect for these, a number of new features in ArchiCAD 17 assist you in achieving collisions, thereby allowing the automatic junction logic to take effect.
Any newly placed elements whose collisions are modeled using the new modeling methods will clean up as expected for ArchiCAD 17.